About Computer Network

BASIC CONCEPT OF NETWORK

Collection of computers and devices connected together via communications devices and transmission media.Usually,the connections between computers in a network are made using physical wires or cables.some connections are wireless, using radio waves or infrared signals.

Applications of network:

TYPE OF APPLICATION	APPLICATION
Resource sharing	Hardware
	Software
Information sharing	Easy accessibility from anywhere
	Search capability
Communication	Email
	Message broadcast

Communication Devices

Any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device.

DEVICES	DESCRIPTION
Dial up modem	A communication 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,Cable Modem)	A communication 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 wirelessy from a notebook computer, a smartphone,or other mobile device
Network Card	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 computer and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wired network
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

Materials or substances capable of carrying one or more signals in a communications channel.

TYPE	EXAMPLE
Physical transmission media	Twisted-Pair Cable,Coaxial cable,Fiber-Optic Cable
Wireless transmission media	Infrared,Broadcast Radio,Cellular Radio,Microwave,communications satellite

Advantage	Disadvantage
Easy for communication	Breakdowns and Possible Loss if Resouces
Ability to share files,data and information	Expensive for the setup and maintenance
High scurity level	Security Threats
High speed	Bandwith Issues