Glossary Of Terms

Here is a list of terms commonly used in the IT world along with explanations for what they mean.

A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   Y   Z

A

Access Point
An access point is a device, like a wireless router, that allows wireless devices such as laptops, or cell phones to connect to the Internet. Wireless routers found in homes, or WI-FI hotspots at the airport or other public places are all considered access points.
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AI - Artificial Intelligence
Artificial Intelligence is often thought of in terms of robots, but is also often used in video games and software simulations. AI is the ability of a computer to "think" in similar terms to a human.
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A Record - Address Record
Servers use IP addresses to define where a computer is located over the internet. However, these IP addresses are difficult for people to remember, so we use domain names. An A record is the part of the DNS that will directly translate a domain name into an IP address.

Example: isoc.net has an A record of 67.96.0.250. When you type isoc.net into a browser, the browser knows to go to the IP address of 67.96.0.250. because of the DNS.
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B

Backbone
Humans have a backbone that serves as the main path for the nerves of the body, that then branches out into smaller nerves. The Internet also has a backbone that works in a similar way. There are several very high bandwidth connections that link many different nodes together around the world that form the backbone of the Internet. Webhosts and ISPs will then branch off of this backbone to their own networks.
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Bandwidth
Bandwidth is how much data can be passed through a connection. An Internet or network connection is often talked about as a "pipe". The bigger the "pipe", the higher the bandwidth of a connection. It can be compared to the roads. An expressway will consist of many lanes, so more traffic can drive through at a quicker pace. If the same amount of traffic tried to pass through a one lane side street, everything would slow down considerably. Same goes for an Internet connection.
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BCC - Blind Carbon Copy
When sending someone an email, you put their address in the "To:" field. You may wish to copy someone else on the email, although they may not necessarily be the main recipient of the message. This would usually be placed in the "Cc:" field which stands for "Carbon Copy". If you wish to send a copy of an email to someone but not want the main recipient to know, or not want to give out that person's email address, you can use the "Bcc:" field, or "Blind Carbon Copy". Any recipients placed in the Bcc field will be hidden from everyone else. This is also useful when sending an email to many people, as you can place them all in the Bcc field so that no one sees everyone else's email address and so can't be captured or used for spam or other purposes.
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Bits/Bytes
Computer storage size is measured in bits and bytes. A bit is the smallest unit of size used. The term "bit" comes from the phrase "Binary DigIT". It takes 8 bits to make just one character such as letter or number in a file. 8 of these bits is one byte. So if you create a text file with one single character in it and save it, it would take up 1 byte of space (or 8 bits). Size then goes up to kilobytes, megabytes, gigabytes and so on. Although people often say there are 1000 bytes in a kilobyte, in truth it is actually 1024. Here are the conversions for the most common sizes.
8 bits = 1 byte
1024 bytes = 1 kilobyte
1024 kilobytes = 1 megabyte
1024 megabytes = 1 gigabyte
1024 gigabytes = 1 terabyte
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Blacklist
A blacklist is a list of usernames or IP addresses that are denied access to a system. Often email administrators will employ blacklists to block emails that come from networks known to host spammers.
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Blog - Web Log
A blog is an online journal or articles posted on the Internet. Blogging is now widespread around the world, so practically anyone can post their opinions or feeling on something for the world to see. You can check out the ISOC Support blog here.
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Botnet
A botnet is basically a group of computers that have are controlled from a single source. They are often used by spammers and hackers to send huge amounts of spam or to create attacks on various websites and networks. Viruses and other malware will often cause a user's computer to become part of a botnet and then used for malicious activies without them knowing it. A botnet can also be used for legitimate purposes such as distributing processing of scientific data.
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Broadband
Broadband refers to a high speed Internet connection. The most common types of broadband connections for users are cable and DSL. Satellite is another type of broadband connection.
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C

Cache
A cache stores recently-used information in a place where it can be accessed extremely fast. Browsers store images and other parts of a website in a cache so it can grab that information more quickly than having to download the same images again.
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CAPTCHA - Completely Automated Public Turing test to tell Computers and Humans Apart
One of the main purposes for using a CAPTCHA is to prevent spammers from using bots to automatically fill in online forms and send a bunch of junk mail. It works by requiring a certain sequence of random letters and/or numbers to be entered before a form can be submitted. The CAPTCHA uses a distorted image that makes it difficult to be read by a bot or computer, but easy enough for a person to read. If the bot can't read it, it can't fill out the field correctly and so the form won't send.
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CC - Carbon Copy
When you "Cc:" someone on an email, you are adding their email address to receive a copy of a particular email.
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Cloud Computing
Cloud computing is really starting to take off all around the world. It refers to applications, services and storage that are available over the Internet. This could be a backup service where the contents of a hard drive is backed up to a location online, or using applications, such as Google Apps, to type up documents and spreadsheets while not having to install software on your computer.
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CNAME - Canonical Name
A CNAME is part of the DNS for a domain. It specifies another name, or alias, for a domain. This second name can be used in the same way as the first name.
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CPU - Central Processing Unit
While many people refer to their computer, or their computer tower as their "CPU", it is in fact not the computer itself. The CPU is the brain of the computer; a computer chip that contains all of the instructions a computer needs to process data.
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CSS - Cascading Style Sheets
A style sheet language used for setting up the look and formatting of a web page written in HTML. This may include such things as layouts, colors and fonts. It works by listing particular styles that can be called by the webpages, saving time from having to write the same style on each page. If a change to a style needs to be made it only has to be made in one place rather than on each webpage.
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D

Defrag - Defragment
When a computer stores information on a hard drive, it breaks it up into small pieces and stores it where ever there are free locations on the hard disk. This results in data being stored all over the place, meaning your computer has to work harder and longer to find all the pieces to a particular file. When you defrag a hard drive, you are taking all of the pieces of data and sorting them out so they are together and quicker to find. So performing a defrag on a regular basis, such as once a month, will keep your computer running faster.
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DHCP - Dynamic Host Configuration Protocol
A server uses DHCP to assign an IP address to a computer on the network.
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DNS - Domain Name System or Domain Name Server
The system used to translate a domain name or URL to an IP address and back again. For example isoc.net is translated to the IP address of 67.96.0.250. DNS consists of records such as A records, MX records and CNAME records.
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DSL - Digital Subscriber Line
A type of broadband Internet connection used over the phone lines that doesn't tie up the phone line like a dialup connection does.
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E

E-commerce - Electronic Commerce
E-commerce is doing business over the internet. Any kind of online store is an e-commerce site.
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Emoticon
Emoticons started off as little text based faces used to try and show the emotion or feeling in email or an online chat. These days many email and chat programs will change the text based faces into little images of a smiling face or something similar.
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Ethernet
The most common type of connection used to connect computers in a network. The ethernet connector and ethernet port look similar to a phone cable and phone jack but they are larger.
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F

FAQs - Frequently Asked Questions
A list of commonly asked questions regarding a particular topic with answers provided.
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Firewall
A firewall is used to protect a computer or network from unauthorized traffic. It restricts the type of data that can be passed through it. Firewalls can be either hardware based (such as a router) or software based (a program installed on a computer).
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FTP - File Transfer Protocol
A protocol (method) for transferring files from one location to another over the internet. Often used for uploading the files that make up a website to the hosting server.
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G

GPS - Global Positioning System
A GPS provides current position, direction and other information such as speed traveled using a satellite navigation system.
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H

Host
A server that houses certain data or services. This could be a website, email or other services.
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HTML - HyperText Markup Language
The primary markup language (a language made up with a set of tags) used by websites over the internet.
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I

ICANN - Internet Corporation For Assigned Names and Numbers
ICANN is a non-profit corporation that allocates IP addresses and manages the domain name system (DNS).
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IM - Instant Message or Instant Messenger
IM is a common method for communicating over the Internet by sending messages back and forth using an instant messaging program. It is a quicker and more efficient way of having a conversation than sending multiple emails back and forth.
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IMAP - Interactive Mail Access Protocol + Internet Message Access Protocol
A protocol (method) for receiving incoming email. When using IMAP for receiving email the email client actually syncs with the mail server rather than downloading it off of the server. The advantage of using IMAP is that it is better for accessing email from more than one location and email deleted from one location is also deleted from the other location(s). The disadvantage is that it can cause a mailbox to fill up quicker as mail is not removed from the server, so it requires more mailbox management.
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IP - Internet Protocol
The method for passing information from one computer to another over the internet. This includes using an IP address which is a set of 4 numbers that are each between 0 and 255. An IP address is the address of a computer or device on the internet. It can be considered similar to a street address of a house as it provides the location of the computer or device.
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IPv4/IPv6
IPv4 is the most widely used version of the Internet Protocol. IP addresses are defined in a set of 4 numbers, each of which are between 0 and 255. This provides almost 4.3 billion addresses for the Internet. However, with so many people now online in some form, whether it be through a computer or through a cell phone, the number of IPv4 addresses available is almost used up. To solve this issue, IPv6 was developed. IPv6 consists of a set of 8 hexadecimal numbers (from 0000 to FFFF) so it might look like this: 2010:2345:7840:849a:bac3:ef34:3901:785f. This allows for a huge number of IP addresses (34 with 37 zeroes after it). The adoption rate of IPv6 has been slow but everyone will have to soon transition over to it as the available IPv4 addresses is expected to run out sometime in 2011.
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ISP - Internet Service Provider
A company that provides internet access, this could be either dialup, DSL, cable, satellite or T1 among other access methods.
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J

JPEG or JPG - Joint Photographic Experts Group
A commonly used method of compression for photos and image files.
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K

Keylogger
A program that records the keystrokes on a computer. Often considered malware as they are often used by hackers to gain usernames and passwords and other private information.
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L

LAN - Local Area Network
A computer network in a local area such as a home, school or office. A LAN can be either wired, wireless or a combination of both. The computers are usually connected together through a hub, switch or router.
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Linux
An alternative operating system (OS) to Windows. Based on the Unix operating system. Linux is a freely distributed operating system. It is available in many different distributions, such as Red Hat, CentOS and Ubuntu.
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List Server
List servers are used to send messages to a mailing list. Most legitimate list servers allow users to subscribe or unsubscribe from the distribution list. List servers are often used to send out mass mailing to customers, such as newsletters or ads for special deals.
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M

MAC Address - Media Access Control Address
An ID number that uniquely identifies each device on a network. Each network card or wireless adapter has its own individual MAC address. MAC addresses are made up of six 2-digit hexadecimal numbers that are separated by colons. A MAC address may look like this: 00:1e:74:a2:f0:82
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Malware
Malware is short for "Malicious Software". Malware is software that performs unwanted and often malicious tasks. This could include viruses, trojans and spyware.
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Modem
Short for Modulator/Demodulater. A modem is a device that allows data to be transmitted from one location to another. They are mostly used to connect to the Internet with. The original modems were dialup modems, but there are now also cable modems and DSL modems that are much faster.
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MX Record - Mail eXchanger Record
An MX record is the part of the DNS that defines where to send any email sent to the domain. MX records don't use IP addresses, but rather a domain name.

Example: The MX record for isoc.net is mailin.isoc.net. So when someone sends an email to an email address at isoc.net, the MX records tells it to send it to the server mailin.isoc.net. However, as computers use numbers rather than words, just like any other domain, mailin.isoc.net also needs an A record so computers and servers know what IP address mailin.isoc.net is located at. So an additional A record is created for mailin.isoc.net that points to the IP address of 65.90.81.50.
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N

NAT - Network Address Translation
NAT translates the internal IP addresses of the computers on a local network into one external IP address. With use of a NAT, only one external IP address is needed for all of the computers inside the network, so everything going out to the Internet is seen as coming from the same IP address regardless of which PC sent it. Inside the network, the computers communicate with each other using their internal IP addresses to differentiate between each other.
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NIC - Network Interface Card
Also referred to as an ethernet card. A NIC is required to connect an ethernet cable to which in turn connects the PC to the network.
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Node
Any device that is connected to a network. This could be a computer, a server, a printer or any other similar device.
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O

OEM - Original Equipment Manufacturer
The refers to the company that makes a product to be sold under another company's brand name.
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OS - Operating System
The software that runs a computer, or mobile device. Examples include Windows (XP, Vista 7), Mac OS X, Linux, Android.
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P

P2P - Peer To Peer Protocol
A method of sharing files without relying on one central server. The processing power and bandwidth is shared among all users.
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PC - Personal Computer
Although PC can be used to describe any kind of personal computer, the term is usually used to refer to Windows or Linux based computers rather than Apple Macs.
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Phishing
The word "phishing" comes from the word it sounds like "fishing" because it works in a similar way. When someone goes "fishing" they try to catch a fish by baiting them and then hooking them. In a similar way scammers will "phish" by baiting someone with an email that looks like it legitimately comes from a bank or eBay or some other website. The email will have a link that looks right, but the actual link itself is bogus and goes somewhere completely different. Once at that site, information is requested, and if given is then captured and can be used to gain access to such things as bank accounts.
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Ping - Packet INternet Groper
An Internet utility used to determine whether a particular IP address is reachable online by sending out a packet and waiting for a response. However, some server will block ping requests. Ping can also be used to find out the IP address of a particular domain. When performing a ping to a domain name, such as isoc.net, the corresponding IP address will also be shown regardless of if the server blocks ping requests or not.
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POP - Post Office Protocol
A protocol for receiving incoming email. The most common method for accessing email. The email client takes what is on the server and places it locally in the email client's inbox. The advantage of using POP is that it keeps your mailbox clear as email is removed from the server as it is downloaded. The disadvantage is that if mail is being accessed from more than one location, when one location grabs the email the other one won't see it, unless the mail clients are set to keep a copy on the server. Like IMAP keeping a copy on the server requires more mailbox management.
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Q

QWERTY
This refers to a standard Latin alphabet based keyboard. QWERTY comes from the fact that the first 5 letters of the keyboard are "qwerty". The original reason behind the layout of the standard keyboard was to reduce the jamming of typebars in typewriters as they moved to strike the paper.
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R

RAM - Random Access Memory
A memory module that is inserted into the motherboard of a computer. It can be thought of in a similar fashion to a regular office desk. In an office, information may be stored in a filing cabinet (on a PC it would be called a hard drive). All the information is there but there is no way to view it from inside the filing cabinet, so you have to take something out of the filing cabinet and put it out on your desk to be able to view it. With a PC, when you open a document or program, it takes it from the hard drive and puts it into RAM so that it can be accessed and used. The more memory you have, the bigger the desk space, and so the more room to put things you need without having to go back and forth to the filing cabinet or hard drive. When the computer is shut down, anything in the RAM is then gone.
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Remote Access
Being able to access and control a computer from another location. ISOCNET now has the ability to use remote access to assist in troubleshooting issues. Click here for more information.
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ROM - Read Only Memory
Different from RAM and from a hard drive. ROM is memory containing hardwired instructions that a computer will use to start up before the operating system loads.
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S

Safe Mode
Safe Mode is the mode that Windows runs with the bare minimum of drivers and system files needed. Safe Mode is used when there are issues with the way Windows is running in normal mode, such as a bad video driver. The video driver wouldn't be loaded and so the issues that were happening as a result of the driver won't prevent you from performing other tasks, such as removing the bad driver.
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SEM - Search Engine Marketing
A form of internet marketing that looks to promote websites by increasing their visibility in search engine result pages, either by use of SEO, or paid placements and contextual advertising.
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SEO - Search Engine Optimization
Techniques used for improving the ranking for a website within a search engine (like Google) for a particular search. The higher the ranking on a search, the more likely the website is to be seen and consequently visited.
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SMTP - Simple Mail Transfer Protocol
The protocol (method) used to send email.
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Social Networking
The increasingly popular way to be able to communicate with others is to use social networking sites, such as Facebook. These sites allow users to be part of a virtual community, sharing things about their lives in an easy way without having to set up their own websites. Businesses now use social networking to get their companies out there and to share information with their customers.
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Spam
Unsolicited email messages usually trying to sell fake products and services or just trying to infect people's computers with viruses and other malware.
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SPF - Sender Policy Framework
A set of rules added to the DNS records of a domain that specifies who is allowed to send email from that particular domain. If a spammer tries to fake an email from that domain email servers can check the SPF record and see that the sender is not allowed for that domain and either reject the email or mark it as spam.
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Spoofing
Spoofing is the practice of faking or deceiving in some way. There are several ways spoofing is done with computers. The most common way is spam. Spammers will spoof or fake the address an email was sent from. This makes it difficult to block spam based on the email address of the sender because it could be (and often is) someone's legitimate email address and because they change them constantly.
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SSL - Secure Socket Layer
A protocol used to encrypt data so it can be passed securely over the internet. Websites often use SSL certificates that allow users to know that the information they pass to the website will be done in a secure fashion.
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T

TCP/IP - Transmission Control Protocol/Internet Protocol
The combination of the Transmission Control Protocol (TCP) and the Internet Protocol (IP) that are the networking protocols used for computers and devices to communicate with each other over the internet.
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Tweet
Thanks to Twitter, the word "tweet" has a whole new meaning, at least in the Internet world. A tweet is a "micro-blog" that is posted to the Twitter status page to essentially tell people what you are doing or thinking.
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U

UI - User Interface
The place where a person can communicate with a machine. The user interface translates information from machine code to a form that can be understood by people and vice versa. A GUI is a Graphical User Interface, where the interface includes graphics such as windows.
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URL - Uniform Resource Locator
A website's address, like www.isoc.net.
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V

Virus
Similar to a virus your child gets at school. Something that makes you sick and spreads easily. Computer viruses make your computer "sick" in any number of ways. It could cause it to send out mass amounts of spam, delete files and programs from your hard drive or totally crash your computer. They can also spread easily and on their own.
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VoIP - Voice over Internet Protocol
A telephone connection made over an Internet connection instead of the plain phone lines. This allows people to talk long distance without paying large phone charges.
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W

WAN - Wide Area Network
A WAN is a computer network that covers a broad area, that may be across a city, a state or even a country. Usually the WAN connects a set of LANs (Local Area Networks). A company may have multiple offices around a city or state. Within each office they would have their own LAN. In order to keep each office connected though, a WAN may be set up to keep each of these local networks communicating with each other.
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Web 2.0
A term used to refer to the second generation of the web. The first generation of the web was a lot of static webpages with different information on them. The second generation web refers to the more interactive style of the web today. Sites with blogs, wikis and social networking are not static pages, but interactive sites, becoming online communities.
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WEP - Wired Equivalent Privacy
A form of wireless encryption. A WEP key is used on a wireless network to prevent unauthorized people from connecting to it. WEP is being replaced by the more secure WPA encryption.
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WHOIS
WHOIS information is the information listed for a domain name. This includes contact information for the domain administrator and technical contact as well as who the domain is registered through and when the domain is currently set to expire.
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WiFi - Wireless Fidelity
Wireless network technology that allows people to connect to the Internet with a wireless connection. Previously it was mainly computers that could connect to a wireless network, but now other devices such as cell phones and blu ray players are also now able to connect to the Internet through a WiFi connection.
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Wiki
A website or part of a website that allows visitors to add and update content to the site. This makes the content of a wiki a collaborative effort. Wikipedia is probably the best known example of a wiki.
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WPA - Wi-FI Protected Access
A much more secure form of wireless encryption. Performs a similar function to WEP but provides a higher level of protection.
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WYSIWYG - What You See Is What You Get
Often pronounced: "wiz-ee-wig" it refers to software where what you see on a document or some other file is what the final output will look like. Microsoft Word and some web page editors are considered a WYSIWYG editor.
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Y

Y2K - Year 2000
This was often referred to as the "Millennium Bug". Back in the early days of computing, computer engineers only used a two-digit format to express the year. So "80" would have referred to "1980". As we approached the year 2000, the worry was that many of the world's computer systems were still running on the two-digit format for the year and so when the clock ticked over to 2000 it would be read as 1900 thereby throwing everything into chaos. There were plenty of doomsday predictions, similar to the current 2012 doomsday predictions. However many systems were updated to start using four-digit year formats and Y2K passed by with little consequence.
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Z

Zero Day Exploit
A zero day exploit is when a security hole in a software program such as Windows, Internet Explorer or Adobe Reader, is being actively exploited by some method like a worm or virus, before the vulnerability is actually widely known about.
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Zip
A method for compressing files. It could be one file or a group of files compressed into one zip file. A zipped file keeps groups of files together easily but also compresses them so they take up less space and therefore take less time to transfer from one place to another.
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