Computer Network.

A Computer network is the connection of two or more computers that are interconnected by a communications channel in order to share resources ( Such as Databases, Printers, etc.) and information.
The computer on the network may be linked through cables, telephone lines, radio waves, satellites, etc.
Example: 10 PCs connected to 1 resources printer

Advantages of Computer Network

1. File Sharing
   1. It allows file sharing and remote file access among all connected hosts.
2. Resource Sharing
   1. Computer networks allow sharing of computer resources like databases, hardware, etc.
3. Faster and Cheaper Communication:
   1. Due to the presence of computer networks communication is faster and cheaper.
4. Increase Cost efficiency
   1. Software with high cost and high system requirements is available online using computer networks they are stored or installed on a system or a server and can be used by a different workstation.
5. Backup and Recovery.
6. A server of the Computer network is used as a backup.
   1. If any data or files are lost on any computer, It is possible to again to recover them from the database.
7. Remote and Mobile Access.
   1. A remote user can access resources of the data using a computer network.

Disadvantages

1. Security Issues :
   1. If a computer is on a network, a computer hacker can get unauthorized access by using different tools.
2. Rapid Spread of Computer Viruses :
   1. Any computer on a network can get affected by computer viruses.
3. Expensive Setup :
   1. The initial setup required different hardware (like a router, printer, hub, etc) and manpower to install a network which makes it costly.
4. Depends on Main File Server :
   1. If the Server fails no host can access the network