Network based on size

Network based on size: 

Basically network is divided in to three parts according to size:

1. LAN

2. MAN

3. WAN

Local area network:

• A group of networks is a computer network that interconnects computers within a limited area such as a school, Laboratory or office building.
• It covers an area up to 5 km in diameter, but usually less than 1km.
• A LAN is capable of accessing and sharing data devices in the LAN.
• The speed of LAN’s network is 10Mbps to 100 Mbps or higher.
• LAN supports a variety of communications transmission mediums such as Ethernet cable (thin cable, thick cable and twisted pair),fibre and wireless transmission.

Advantage of LAN:

• Resource sharing (Printers, Scanners Modems, Hard disks can be shared within the connected devices).
• This reduces cost and hardware purchase.
• Easy and cheap communication
• Centralized data
• Internet sharing

Disadvantage of LAN:

• High setup cost(Ethernet cable, switches, hubs)
• Privacy violations
• Data security
• Covers limited area

Metropolitan area network:

• A metropolitan area network is a network that interconnects users with computer, resources in a geographical area larger than that covered by LAN but smaller than the area covered by a WAN.
• It covers an area between 5-50km in range.
• MAN’s are formed by connecting multiple LAN's. 
• Generally it is a network that  spreads over a city.

Advantages:

• Less expensive
• High speed than WAN
• Conversion of LAN to MAN is easy.
• High security

Disadvantage:

• Difficult to manage
• Hackers attack
• Need more wires
• Technical staff is required to set up.

Wide area network:

• The network, which is spread over the globe and covers the entire world, is facilitated to a computer by Internet service providers.
• It is the biggest network across the world in that each computer is connected and shares or accesses the data and information.
• Through a wide area network, we can access the information stored away on the web server in seconds.
• The only thing we need is to know the address of that data or information stored.

Advantage:

• WAN covers a larger geographical area. Hence business offices situated at longer distances can easily communicate.
• It allows sharing of resources.
• It supports the global market and global business.
• It uses advanced technologies.

Disadvantage:

• Initial investment costs are higher
• Difficult to maintain
• Slow speed of data transfer
• It has lower security compared to LAN and MAN due to wider coverage.
• There are more errors and issues due to wide coverage.