4G Definition 4G is a collection of fourth generation cellular data technologies. It succeeds 3G and is also called "IMT-Advanced," or "International Mobile Telecommunications Advanced." 4G was made available as early as 2005 in South Korea under the name WiMAX and was rolled out in several European countries over the next few years. It became available in the United States in 2009, with Sprint being the first carrier to offer a 4G cellular network. All 4G standards must conform to a set of spe...

iSCSI Definition Stands for "Internet Small Computer Systems Interface." iSCSI is an extension of the standard SCSI storage interface that allows SCSI commands to be sent over an IP based network. It enables computers to access hard drives over a network the same way they would access a drive that is directly connected to the computer. iSCSI is a popular protocol used by storage area networks, which allow multiple computers to share multiple hard drives. For example, data centers can be spread ...

SMTP Definition Stands for "Simple Mail Transfer Protocol." This is the protocol used for sending e-mail over the Internet. Your e-mail client (such as Outlook, Eudora, or Mac OS X Mail) uses SMTP to send a message to the mail server, and the mail server uses SMTP to relay that message to the correct receiving mail server. Basically, SMTP is a set of commands that authenticate and direct the transfer of electronic mail. When configuring the settings for your e-mail program, you usually need to s...

LDAP Definition Stands for "Lightweight Directory Access Protocol." If you want to make directory information available over the Internet, this is the way to do it. LDAP is a streamlined version of an earlier directory standard called X.500. What makes LDAP so useful is that it works great over TCP/IP networks (unlike X.500), so information can be accessed through LDAP by anyone with an Internet connection. It is also an open protocol, which means directories can be stored on any type of machine...

Meme Definition A meme is a concept or behavior that spreads from person to person. Examples of memes include beliefs, fashions, stories, and phrases. In previous generations, memes typically spread within local cultures or social groups. However, now that the Internet has created a global community, memes can span countries and cultures across the world. Memes that are propogated online are called "Internet memes." Examples of behavioral Internet memes include using Facebook and checking email...

HTTP Definition Stands for "Hypertext Transfer Protocol." HTTP is the protocol used to transfer data over the web. It is part of the Internet protocol suite and defines commands and services used for transmitting webpage data. HTTP uses a server-client model. A client, for example, may be a home computer, laptop, or mobile device. The HTTP server is typically a web host running web server software, such as Apache or IIS. When you access a website, your browser sends a request to the correspondi...

VoIP Definition Stands for "Voice Over Internet Protocol," and is often pronounced "voip." VoIP is basically a telephone connection over the Internet. The data is sent digitally, using the Internet Protocol (IP) instead of analog telephone lines. This allows people to talk to one another long-distance and around the world without having to pay long distance or international phone charges. In order to use VoIP, you need a computer, an Internet connection, and VoIP software. You also need either ...

SIP Definition Stands for "Session Initiation Protocol." SIP is a protocol defined by the Internet Engineering Task Force (IETF). It is used for establishing sessions between two or more telecommunications devices over the Internet. SIP has many applications, such as initiating video conferences, file transfers, instant messaging sessions, and multiplayer games. However, it is most well known for establishing voice and video calls over the Internet. VoIP companies, such as Vonage, Phone Power, ...

TTL Definition Stands for "Time To Live." Pretty intense for a computer term, huh? It refers an aspect of the Internet Protocol. TTL is used when a "ping," or a request for a response, is sent to another computer, such as a server. The TTL represents the number of hops, or servers in different locations, the request can travel to before returning a failed attempt message.

Payload Definition When data is sent over the Internet, each unit transmitted includes both header information and the actual data being sent. The header identifies the source and destination of the packet, while the actual data is referred to as the payload. Because header information, or overhead data, is only used in the transmission process, it is stripped from the packet when it reaches its destination. Therefore, the payload is the only data received by the destination system.