Definition of network/computer network:

• A network is a collection of computers and mobile devices connected together via communication devices and transmission media, often wirelessly allowing computers to share resources (hardware,software,data and information)

Computer network usage:

• Sharing internet connection among several users.
• Sharing application software, printers and other resources.
• Facilitating Voice over IP(VoIP),e-mail, video conferencing, messaging, and other communications application.
• Exchanging fies among network users and over the internet.

Communication Devices

• Definition - Hardware component that enables a computer to send (transmit) and receive data,instruction and information to and from one or more computers
• Example - cable modem, wireless modem, network cards, hubs and switches

Communication devices terms

Terms	Definitions
Modem	A device that enables a computer to communicate over analog networking media such as connecting the internet via telephone lines.
Router	A device that connects multiple networks together.
Wireless access point	A device on a network that connects wireless devices to that network.
Switch	A device use to connect multiple devices on a single (typically wired) network.
Hub	The device that provides a common central connection point for nodes on network.
Repeater	A device that enhance teh weaken signal and repeat it at its original strength.

Transmission Media

• Definition - The type of physical system used to carry a communication signal from one system to another.

Type of transmission media:

Type	Example
Physical : send signals through cable, wire or tangible materials	Twisted-pair cable Coaxial cable Fiber optic
Wireless : send signals through the air or space	Infrared Microwaves Cellular radio Broadcast radio Communication satellites Bluetooth

Advantages of network	Disadvantages of network
Hardware sharing - Network facilitate the sharing of hardware devices suach as printer, plotters and modem.	Undesirable sharing - Viruses are easily spread over network and the internet.
Data and information sharing - enable many people to access and share the same data such as database and group software development.	Security issues - a computer hacker can get unauthorized access by using different tools.
Fcilitate communication - People communicate efficiently and easily via e-mail, IM, VoIP.	Network hardware,software and setup costs - Setting up a network requires an investment in hardware,software of network.