Network and Communication

A network is a set of devices (often referred to as nodes) connected by communication links. Or a network is simply two or more computers that are linked together. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.

Benefits of a Network:

1. Information sharing –
   Authorized users can use other computers on the network to access and share information and data. This could include special group projects, databases, etc.
2. Hardware sharing –
   One device connected to a network, such as a printer or a scanner, can be shared by many users.
3. Software sharing –
   Instead of purchasing and installing a software program on each computer, it can be installed on the server. All of the users can then access the program from a single location.
4. Collaborative environment –
   Users can work together on group projects by combining the power and capabilities of diverse equipment.

Network Criteria:
A network must meet the following network criteria:

1. Performance –
   It measured by transit time and response time[also depends on users, medium, hardware, software.
2. Reliability –
   It measured by the frequency of failure.
3. Security –
   It protecting data from unauthorized access.

Risks of network computing:
The security of a computer network is challenged every day by:

• Equipment malfunctions
• System failures
• Computer hackers
• Virus attacks

Note:
Equipment malfunctions and system failures may be caused by natural disasters such as floods, storms, or fires, and electrical disturbances

Categories of Networks:
It is categorized into three types: LAN, MAN, WAN. Into which categories of network falls is determined by its size, its ownership, the distance it covers, and its physical architecture.

1. LAN:
   It is usually privately owned and links the devices in a single office, building, or campus. Its size is limited to a few kilometres. It is designed to allow resources (h/w, s/w or data) to be shared between personal computers or workstations. In general, a given LAN will use only one type of transmission medium. The most common LAN topologies are bus, ring, and star.
2. MAN:
   It is designed to extend over an entire city. A company can use MAN to connect the LANs in all its offices throughout a city. Maybe wholly owned and operated by a private company or it may be service provided by a public company (local telephone company).
3. WAN:
   It provides long-distance transmission of data over a country, a continent, or even the world wide. Maybe wholly owned and operated by a single company is referred to as an enterprise network.