A Computer Network is a group of computers connected to each other via a network. This network is used to transmit data between different computers. A computer in a network is called a node.
Computer Network History
Computer network history goes back to the 1950s where computers were so new. Below we will list some of the important points of the computer network.
- First computer networks are created in the late 1950s in the U.S. military radars named SAGE.
- In 1963 the first general computer network is proposed.
- The first packet switching network is created throughout the 1960s and used in the National Physical Laboratory in the United Kingdom. The speed was about 768 kbit/s.
- In 1969 the first4 nodes of ARPANET are connected using 50 kbit/s from UCLA, Standford, University of California, and the University of Utah.
- In 1972 commercial services using X.25 provided and later this network is integrated TCP/IP protocol suite.
- In 1973 Robert Metcalfe created the Ethernet protocol which is based Aloha network.
- In 1974 Vint Cerf, Yogen Dalal, and Carl Sunshine created the Transmission Control Protocol (TCP).
- In 1977, the first long-distance fiber network was deployed in Long Beach, California.
- In 1980, Ethernet was upgraded to the 10 Mbit/s speed.
Computer Network Use Cases
Today computer networks are critical, and without the computer network most of the computer operations will stop. The Internet is the biggest computer network that provides communication and data transmission capabilities to computers around the world. Today computer networks are used for different purposes and cases like below.
- Playing online games with players over the world.
- Sharing files and folders with other computers.
- Accessing web sites
- Chat and video call
- Being social with social media
- Making research
- Sharing resources
- Email messaging
- Ecommerce
- Money sending and economical operations
- Access printers
Computer Network Types
Computer networks are categorized according to their range and physical distance.
Personal Area Network (PAN)
Personal Area Network or PAN is the smallest computer network that is mainly used to connect devices used by humans. Bluetooth is the most popular PAN protocol used to connect smartphones, speakers, and personal devices.
Local Area Network (LAN)
Local Area Network or LAN is the most popular network type where nodes/devices/computers are connected in a limited distance like the same house, same floor, same room, or same building. LAN nodes use Ethernet for transmission between each other.
Metropolitan Area Networks (MAN)
Metropolitan Area Network or MAN is used to connect devices for long distances like in a city.
Wide Area Networks (WAN)
Wide Area Network or WAN is used to connect computer networks between different countries, areas and continent.
Internet and Intranet
Computer Network Topologies
Computer networks can be created in different formations which can be categorized and named in different names. These formations are called Computer Topology. Computer Topology mainly used computer networks physical connections but can be also used for logical connections. Below are the most common topologies or layouts for computer networks. Internet uses the “Mesh topology” by the way.
Bus Topology
In Bus Topology all computers are nodes are directly connected to a common medium like bus way and stations where stations are nodes.
Star Topology
In Star Topology all computers are connected to a special central node which is generally a network device. The nodes and connections are similar to the star.
Ring Topology
In Ring Topology nodes/computers has connected to the left and right node/computer. This will form a ring.
Mesh Topology
In Mesh Topology there is not specific connection count and type where different computers/nodes has different connectiontion. Internet is the biggest mesh topology network where different computers has different phyiscal connections others.
Fully Connected Topology
In Fully Connected Topology all nodes/computers are connected to each other. This is very expensive to implement and hard to operate.
Tree Topology
In Tree Topology computers are nodes of the tree. This tree has a hierarchycal connection between nodes and networks.
Computer Network Components
In order to create and run a computer network some of the following devices are required.
- Host
- Server
- Router
- Switch
- Hub
- Firewall
- Access Point
Host
Host is a generic name used for different types of devices. Computer, PC, Laptop, Smartphone, SmartTV are a host devices too. Host devices mainly consume data, service provided by the servers.
Server
Server is a computer type where provides data and services to be used by other hosts. Server have services to serve some information and use computer network for the transmission of data.
Router
Router is important parts of the computer networks where they route data between different hosts or servers. Routers store the routes to the different networks and redirect packets properly.
Switch
Switch is another important network device for a computer network that is used to connect multiple hosts and servers with the routers. The switch works on OSI layer 3.
Hub
Hub is a old type network devices which is similar to the switch.
Firewall
Firewall is a computer network security devices which is used to detect, monitor and prevent cyber attacks over computer network.
Access Point
Access Point is a computer network devices used to provide network connection without a cable via air.
Modem
Modemis a devices used to connect local network to the POP point which is generally the ISP.
Computer Network Terms
Computer networks are very complex and contains a lot of different technologies, protocols, devices with different terms. Below we will list some of the most popular terms elated with the computer network.
IP Address is a numerical representation used for the hosts and servers.
Mac Address is the address of the network interface card which is generally an ethernet or wireless card.
Port is a logical gate used to specify the local and remote service we want to connect.
DNS or Domain Name System is the protocol used to link names with the IP addresses like poftut.com is resolved to the 192.168.1.1 IP address.