What does Computer Network mean?
A computer network is a broad term for one of the biggest technological advances in computer science over the last 40 years. The basic definition of a computer network is that a computer network connects parts of a distributed architecture, whether those parts are made up of hardware, or virtual or logical resources.
Networks are commonly categorized based on their characteristics.
Techopedia explains Computer NetworkWe’ll talk more about how this distinction is made in the evolution of computer networking step-by-step, from the early mainframe computers onward.
The earliest computers had no networks — they were monoliths that crunched numbers through basic mechanical and electrical components.
Then, slowly, as the technology evolved, we figured out how to link one physical computer to another.
Different types of private networks are distinguished based on their sizes (in terms of the number of machines), their data transfer speeds, and their reach.
Private networks are networks that belong to a single organization.
There are usually said to be three categories of such networks:
LAN, or local area network; MAN, or metropolitan area network; and WAN, or wide area network.
There are also two other types of networks: TANs and CANs.
LAN Network Definition.
LAN refers to a group of computers that all belong to the same organization. They are linked within a small geographic area using a network and often the same technology (the most widespread being Ethernet).
MAN Network Definition.
What is “MAN network”? MANs connect multiple geographically close LANs (over an area of up to several dozen miles) to one another at high speeds. Thus, a MAN lets two remote nodes communicate as if they were part of the same local area network.
A MAN is made from switches or routers connected to one another with high-speed links (usually fibre optic cables).
WAN Network Definition.
A WAN connects multiple LANs to one another over great geographic distances. The speed available on a WAN varies depending on the cost of the connections: it increases with distance, and can be low.
WANs operate using routers that can choose the most appropriate path for data to take to reach a network node. The most well-known WAN is the Internet.
TANs and CANs_
TANs, or Tiny Area Network is the same as LANs but smaller, consisting of 2 to 3 machines.
CANs, or Campus Area Networks is the same as MANs, with bandwidth limited between each of the network’s LANs.
_ Types of computer networks according to the method of connection.
Computer networks are divided according to the way they are connected into many different types, and among these types are the following:
1. STAR TOPOLOGY .
In the star network, devices are connected to a central computer called the hub. Nodes communicate over the network by passing data over the hub.
2. BUS TOPOLOGY .
The bus is the central cable – the main wire – that connects all devices on a local area network (LAN). It is also called the spine. This is often used to describe the main network connections that make up the Internet. Bus networks are relatively inexpensive and easy to install for small networks.
3. RING TOPOLOGY.
That is, all nodes are connected in a closed loop. Messages travel around the loop, as each node reads those messages addressed to it.
4. TREE TOPOLOGY.
This “hybrid” network combines the characteristics of a linear chassis and a star bus. In a tree network, network clusters made up of stars are connected to a linear backbone cable.
Computer Network”, www.techopedia.com
Types of Networks”, ccm.net