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Accumulator
The most important of the internal CPU registers,
which contains the results of an operation or process to be carried out.
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Addressing
In the network world, every device needs an identifying number that is unique
to that device. Usually these identifiers are made up of some combination of
numbers. For network, and internetwork communications to occur each device needs
to have this unique numeric ID, or address. For purposes of this discussion
there are two important types of addressing: IP addresses and MAC
layer addresses.
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Arithmetic Logic Control (ALU)
Hard ware section of the CPU that carries out all the mathematical
and logical functions.
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Back Plane
Part of the body of the computer, which holds the circuit boards, buses
and expansion connectors. Also known as the motherboard or process control board
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Bandwidth
The amount of data that can be sent through a given communications circuit per
second.
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Buses
Communication link consisting of leads or wires which connect various hardware
systems. Over these links data is transmitted and received. Buses can
be internal /external, dedicated point to point or multipoint multi drop.
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Central Processing Unit (CPU)
Group of circuits which perform the basic functions of a computer. It is
made of three parts , namely the Arithmetic Logic Unit, the
Control Unit and Input/Output unit.
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Clock rate (clock speed)
The clock rate is measured in Hertz which is the units of completed cycles per
second.
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Control Unit (CU)
Area of the CPU which is responsible for selecting and
executing instructions
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Fetch Execute Cycle
Series of events that take place during the fetching , decoding and implementation
of an instruction retrieved from memory. The cycle can be divided in two subcycles
know as the instruction cycle, where data is 'fetched' and the execute cycle
where instructions are 'executed'.
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FTP File Transfer Protocol.
This is the protocol that is used in order to make it possible for files to
be transferred across a network from one computer to another.
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Gateway
A gateway is a machine that connects a network of hosts to another network.
On the Internet gateways function as routers, passing
messages along until they reach their destination.
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Gopher
Gopher is another information retrieval feature of the Internet. Gopher sites
are an alternative to web sites. Hierarchical text based menus lead the searcher
to their final choice. Some websites provide links to Gopher sites and visa
versa.
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Interface
A boundary across which two systems communicate. An interface might be a
hardware connector used to link to other devices, or it might be a convention
used to allow communication between two software systems.
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Instruction Set
Total number of instructions that a processor can recognise and execute.
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Internet
A world wide network of networks which offers a number of different opportunities.
The two most popular ones are Email and the World Wide Web. In its infancy it
was know as ARPANET.
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IP Addresses
IP addresses are unique numerical addresses based on a standard scheme and assigned
by a central governing body. They are used to communicate between nodes on an
internetwork.
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MAC Layer Addresses
Media Access Control addresses are the hardware addresses used by nodes
on a network to identify and locate one another. They are used to communicate
between nodes on the same wire and are most often built right in to the NICs
used for network communications. MAC addresses are the lowest level of network
identifiers and provide the final links by which information is passed from
device to device on a network
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Mbps.
This is an abbreviation for mega bits per second, meaning a million (10 to the
power of six) bits per second.
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Network
A network is any collection of machines or devices connected physically by some
type of physical transport medium (i.e., wire). Network devices may all be on
the same wire or they may be connected over a series of wires using bridges
or repeaters. Networks may be as few as 2 computers , but size can extend as
far as the Internet.
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Node
A node also know as a host is any machine connected to a network or internetwork.
A special case of which is the end node, a station where users perform work
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Packet / Datagram
Information is carried across networks in sub-blocks called packets or datagrams.
Transmission of uniform packets of information allows for many hosts on a network
to communicate simultaneously over the same transport medium. As well as the
body of data, packets or datagrams contain information in a header that allow
for error detection and correction transfer across the network.
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Protocol
A protocol, in networking, is a set of rules that specifies the formation of
network packets and sets forth the ways these packets are handled on the network.
Each protocol is designed to deal with a specific function or collection of
functions.
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Register
Special location with in the CPU used to hold data and
address which are to be processed. Registers may be general purpose or reserved
for a special use, such as the program counter and instruction registers used
during the Fetch Execute Cycle.
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Routers
Routers are machines that connect nodes on a network. Routers perform all the
functions offered by the network operating system and are responsible for knowing
how the network topology is configured and transferring information from one
part of the network to another.
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Telnet
A facility built into many web browsers whereby one's computer can be turned
into the terminal of a distant server computer. It enables people to do such
things as download software or play computer games with others across a network.
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Wide Area Networks (WAN's)
A network that covers a wide geographical area. This size of this area can infact
vary enormously, ranging from across a city to across the world.
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World Wide Web / WWW
Collection of Millions of web sites and pages that go to make up part of the
Internet
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