Computer Network

What Is Network?

A network is a collection of computers and devices connected together via communications devices and transmission media.

Communication Devices

A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device.

Dial-up Modem A communications device that can convert digital signals to analog signals and analog signals to digital signals, so that data can travel along an analog telephone line.
Digital Modem (ISDN, DSL and Cable Modem) A communications device that sends and receives data and information to and from a digital line.
Wireless Modem Some mobile users have a wireless modem that uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device
Network Card Sometimes called a network interface card, is a communications device that enables a computer or device that does not have built-in networking capability to access a network.
Wireless Access Point A central communications device that allows computers and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wired network . *Wireless access points have high-quality antennas for optimal signals.
Router A communications device that connects multiple computers or other routers together and transmits data to its correct destination on a network.
Switch A connection device similar to a hub but more sophisticated, including functionality that allows it to control and manage data transmissions.
Hub A connection device that allows multiple connections to the network.

Transmission Media

Transmission media is materials or substances capable of carrying one or more signals in a communications channel. There are two types of transmission media that is Physical Transmission Media and Wireless Transmission Media

Advantage & disadvantage of network 

Advantage	Disadvantage
Easy to communicate	Expensive to build
Easy to share data & Information	Security Threats
Can share information	Bandwith issue