1844 (Samuel Morse):
Sent first telegraph message used dots and dashes to represent letter and numbers, 37 miles from Washington DC to Baltimore.

1867 (Alexander Graham Bell): Invented Telephone
1960 – 1970: Computer communication was centralized around Mainframe Host.
1981: Birth of Personal Computer

Department of Defense (USA):
Perceived the idea of network for the purpose of security. DOD (Department of Defense) with the help of Advance Research Project Agency (ARPA) created the first network called ARPANET.
By the mid 1980s, commercial organization could also connect to this growing network, now referred as Internet.

NETWORK:
A set of interconnected devices with something to share. The share resource could be data, printer, DVD-ROM and Internet etc.
And the concept of connected computers sharing resources is called Networking.

TYPES OF NETWORK:

LAN (Local Area Network):

• A network spread in a small area.
  Example: A network is a room, the floor of building etc.
• Range 100 meters to 3 Kms.
• Provide high speed (10 Mbps to 10 Gbps)
• Also known as Broadcast Domain

Hardware Components used in LAN:

• Media connectors
• Network Interface Card
• Repeater
• Bridge
• Hub / Switch
  Etc.

Note: Sanwa Cat7a first adapted by Japan gives 10 Gbps.

MAN (Metropolitan Area Network):

• A network spread in a town or city.
• A network larger than LAN and smaller than WAN.
• Normally covers the area inside town or city.
• Used to connect offices branches within the city.
• Transmission media used: Coaxial cable, Fiber optics, Microwave etc.
• Range: upto 60 Kms. 

Hardware Components used in LAN:

• All hardware components used in LAN (plus)
• Telephone line (DSL, Lease Line, Frame relay etc.)
• Modem
• Gateway
• Router
  Etc.

WAN (Wide Area Network):

• A network spread in a very large area, spread all over country or world.
• A network between devices that are very far apart.
• A WAN consist of LANs and MANs
• Example: A network between India and US, Delhi and Bangalore etc.
• One of the most prominent examples of WAN is Internet.
• Range: It may cover the country even the world.
• Less speed than LAN.
• Less reliable than LAN.
• Computers in WAN are often connected through public networks such as telephone line, Lease line, Satellite etc.

Hardware Components used in WAN:

• All hardware components used in LAN (plus)
• Satellite
• Telephone line (DSL, Lease Line, Frame relay etc.)
• Modem
• Gateway
• Router
Etc.