What is Computer Network - Definition of Computer Network
What is computer Network - A computer network is defined as a set of Computers which are connected together for the purpose of sharing data from one computer to another. The most common technology which is used today to join more than one computer is Internet. The computer from remote places can be connected via Internet. We go in details regarding Internet in next article. Here we will give more emphasis on computer networks. The computer or PC can be connected by a printer using computer network technology. The medium may be physical or invisible which we call WIFI, Bluetooth, Infrared etc. In this topic we will discuss in details the types of computer networks by which more than one computer can be connected. There are several different types of computer networks. Computer networks can be characterized by their size as well as their purpose.
What are the Types of Networks?
There are various types of network technology by which more than one computer can be connected. These are –
- LAN (Local Area Networks) - A local area network (LAN) is a network that connects more than one computers or devices in a limited geographical area such as a home, school, office building, or closely situated buildings. Each computer or device on the network is called as a node. This wired LAN technology uses Ethernet technology. The LAN are capable of transmitting data at a very fast rate, much faster than data can be transferred over a telephone line; but the distances are limited and there is also a limit on the number of computers that can be attached to each other.
The smallest LAN may only use two computers, while larger LANs can accommodate thousands of computers.
- WAN (Wide Area Network) - A wide area network, or WAN, occupies a very large area, such as an entire country or entire world. A WAN can contain multiple smaller networks, such as LANs or MANs. The Internet is the best example of a public WAN.
- MAN (Metropolitan Area Network) - A metropolitan area network, or MAN, consists of a computer network across an entire city, college campus and small region. A MAN is larger than a LAN, which is limited to a single building or site. Depending on the configuration, this network can cover an area from several miles to tens of miles.
- SAN (Storage area network) – SAN is a high-speed network of storage devices that connects storage devices with servers. It provides block-level storage that can be accessed by the applications running on networked servers. SAN storage devices can include tape libraries, disk-based devices and etc., like RAID hardware. The major functions of SAN are - A high-speed network of storage devices, connects the storage devices with servers, helpful in backup and disaster recovery, simplify some management tasks and others.
- PAN (Personal area network) – A personal area network (PAN) is a computer network used for data transmission among devices like computers, telephones, tablets, PDA and others. Example – Connecting Computer with Printer via WIFI, Phone WIFI is used for running application in computer etc. Personal area networks can be wireless or build with cables. USB and FireWire often link together a wired PAN, while WPANs typically use Bluetooth or infrared connections.
- EPN (Enterprise private network ) – An enterprise private network is a computer network used by a businessman to interconnect its various company sites (such as manufacturing sites, offices and shops) in order to share information from one place to another.
- VPN (Virtual Private Network) - A virtual private network (VPN) is a network that are used using public wires — Via Internet — to connect to a virtual private network, such as a company's own network. There are a number of systems by which you can create networks using the Internet as the medium for transporting data. A VPN secures the private network, using encryption and other security mechanisms ensuring that only the authorized users can access the network and the data cannot be intercepted or interrupted.
What is Computer Network - The answer is continued.
What is Network Topology?
The network topology is the arrangement of various links or nodes or connecting wires in a computer network. How the computers, nodes, central power are connected to each other is decided by network topology. There are many types of Network topology in which the main are – Star, Bus, Ring, Mess etc. We will discuss each one by one. The arrangement of machines with each other is different in these topology.
What are Star Topology?
In Star topology, all the components of network are connected to the central device called "hub" which may be a hub, a router or a switch. Here all the workstations are connected to central device with a point-to-point connection. All the data on the star topology passes through the central device before reaching the intended destination.
Advantages of Star Topology
- Performance of the network depends upon the capacity of central hub.
- Easy to connect each new nodes or devices.
- It helps in monitoring the network easily
- Failure of one node or link doesn't affect the rest of network system
Disadvantages of Star Topology
- Whole network fails when hub or central device fails.
- Too much dependency in central device
What are Bus Topology?
Bus Topology is the simplest form of network topologies. In this type of topology, all the nodes are connected to the single cable (called bus). This central cable is the backbone of the network. Every workstation communicates with the other device through this Bus. A signal from the source is released and it travels to all workstations connected to bus cable.
Advantages of Bus Topology
- The installation cost is less for this topology.
- It is good for small network
- Easy to set up and extend.
Disadvantages of Bus topology:
- There is a limit on central cable length and number of nodes that can be connected
- Maintenance costs can get higher with time.
- It is not suitable for networks with heavy traffic.
- It is difficult to detect and troubleshoot fault at individual station.
What are Mess Topology?
In Mess topology each of the network node, computer and other devices, are interconnected with one another. Every node not only sends its own signals but also relays data from other nodes. In fact a true mesh topology is the one where every node is connected to every other node in the network. This type of topology is very expensive as there are many redundant connections, thus it is not mostly used in computer networks.
Advantages of Mess Topology
- The data can be transmitted from all devices simultaneously. This topology can tolerate high traffic.
- Expansion and modification in topology can be done without disturbing other nodes.
Disadvantage of mess topology:
- There are high chances of data redundancy in different network connections.
- Overall cost would be high.
- Maintenance and set up is difficult.
What are Ring Topology?
In Ring Topology, all the nodes are connected to each-other in a way that they make a closed loop. Each workstation is connected to 2 other components on either side, and it communicates with these two adjacent neighbours. Data travels around the network, in one direction only. Sending and receiving of data takes place by the help of Token.
Advantages of Ring Topology
- Each of the computer has equal access to resources.
- Even when the load on the network increases, its performance will be better.
- There is no need to control the connectivity between workstations by network servers.
Disadvantages of Ring Topology
- Network is highly dependent on the wire which help in connecting devices.
- If one Computer or port goes down, the entire network gets affected.
- Each packet of data should pass through all the computers between source and destination.
So this is some information regarding What is Computer Network. We will discuss some more topics in next article.