Gateway
Either hardware or software that acts as a bridge between two
applications or networks so that data can be transferred among a number
of computers. When e-mail gets sent between two servers or when you log
in to a web site, the gateway helps the connection take place.
Gbps
Short for Gigabits per second, a data transfer speed measurement for high-speed networks such as Gigabit Ethernet.
When used to describe data transfer rates, a gigabit equals 1,000,000,000 bits.
Hop
An intermediate connection in a string of connections linking two network devices.
On the Internet, for example, most data packets need to go through
several routers before they reach their final destination. Each time
the packet is forwarded to the next router, a hop occurs.
The more hops, the longer it takes for data to go from source to
destination. You can see how many hops it takes to get to another
Internet host by using the PING or traceroute utilities.
Host
(1) (n) A computer system that is accessed by a user working at
a remote location. Typically, the term is used when there are two
computer systems connected by modems and telephone lines. The system
that contains the data is called the host, while the computer at which
the user sits is called the remote terminal.
(2) A computer that is connected to a TCP/IP network, including the Internet. Each host has a unique IP address.
HTTP
Short for HyperText Transfer Protocol, the underlying protocol used by the World Wide Web.
HTTP defines how messages are formatted and transmitted, and what
actions Web servers and browsers should take in response to various
commands.
For example, when you enter a URL in your browser, this actually sends
an HTTP command to the Web server directing it to fetch and transmit
the requested Web page.
Hub
A common connection point for devices in a network.
Hubs are commonly used to connect segments of a LAN. A hub contains
multiple ports. When a packet arrives at one port, it is copied to the
other ports so that all segments of the LAN can see all packets.
IMAP
Short for Internet Message Access Protocol, a protocol for retrieving e-mail messages.
The latest version, IMAP4, is similar to POP3 but supports some additional features.
For example, with IMAP4, you can search through your e-mail messages
for keywords while the messages are still on mail server. You can then
choose which messages to download to your machine.
Like POP, IMAP uses SMTP for communication between the e-mail client and server.
IP Address
An identifier for a computer or device on a TCP/IP network.
Networks using the TCP/IP protocol route messages based on the IP
address of the destination. The format of an IP address is a 32-bit
numeric address written as four numbers separated by periods. Each
number can be zero to 255. For example, 1.160.10.240 could be an IP
address.
The four numbers in an IP address are used in different ways to
identify a particular network and a host on that network. The InterNIC
Registration Service assigns Internet addresses from the following
three classes.