Types of Computer Networks

A computer network is a system that connects many independent computers to share information (data) and resources. The integration of computers and other different devices allows users to communicate more easily. It is a collection of two or more computer systems that are linked together. A network connection can be established using either cable or wireless media. Hardware and software are used to connect computers and tools in any network.

Uses of Computer Networks

• Communicating using email, video, instant messaging, etc.
• Sharing devices such as printers, scanners, etc.
• Sharing files.
• Sharing software and operating programs on remote systems.
• Allowing network users to easily access and maintain information.

Types of Computer Networks

There are mainly five types of Computer Networks

1. Personal Area Network (PAN)
2. Local Area Network (LAN)
3. Campus Area Network (CAN)
4. Metropolitan Area Network (MAN)
5. Wide Area Network (WAN)

1. Personal Area Network (PAN)

PAN is the most basic type of computer network. It is a type of network designed to connect devices within a short range, typically around one person. It allows your personal devices, like smartphones, tablets, laptops, and wearables, to communicate and share data with each other. PAN offers a network range of 1 to 100 meters from person to device providing communication. Its transmission speed is very high with very easy maintenance and very low cost. This uses Bluetooth, IrDA, and Zigbee as technology. Examples of PAN are USB, computer, phone, tablet, printer, PDA, etc.

Types of PAN

Wired Personal Area Network: A wired personal area network is constructed using a USB.

Wireless Personal Area Networks: Wireless Personal Area Networks are created by simply utilising wireless technologies such as WiFi and Bluetooth. It is a low-range network.

Advantages of PAN

• PAN is relatively flexible and provides high efficiency for short network ranges.
• It needs easy setup and relatively low cost.
• It does not require frequent installations and maintenance
• It is easy and portable.
• Needs fewer technical skills to use.

Disadvantages of PAN

• Low network coverage area/range.
• Limited to relatively low data rates.
• Devices are not compatible with each other.
• Inbuilt WPAN devices are a little bit costly.

Applications of PAN

• Home and Offices
• Organizations and the Business sector
• Medical and Hospital
• School and College Education
• Military and Defense

2. Local Area Network (LAN)

LAN is the most frequently used network. A LAN is a computer network that connects computers through a common communication path, contained within a limited area, that is, locally. A LAN encompasses two or more computers connected over a server. The two important technologies involved in this network are Ethernet and Wi-fi.  It ranges up to 2km & transmission speed is very high with easy maintenance and low cost. Examples of LAN are networking in a home, school, library, laboratory, college, office, etc.

Advantages of a LAN

• Privacy: LAN is a private network, thus no outside regulatory body controls it, giving it a privacy.
• High Speed: LAN offers a much higher speed(around 100 mbps) and data transfer rate comparatively to WAN.
• Supports different transmission mediums: LAN support a variety of communications transmission medium such as an Ethernet cable (thin cable, thick cable, and twisted pair), fiber and wireless transmission.
• Inexpensive and Simple: A LAN usually has low cost, installation, expansion and maintenance and LAN installation is relatively easy to use, good scalability.

Disadvantages of LAN

• The initial setup costs of installing Local Area Networks is high because there is special software required to make a server.
• Communication devices like an ethernet cable, switches, hubs, routers, cables are costly.
• LAN administrator can see and check personal data files as well as Internet history of each and every LAN user. Hence, the privacy of the users are violated
• LANs are restricted in size and cover only a limited area
• Since all the data is stored in a single server computer, if it can be accessed by an unauthorized user, can cause a serious data security threat.

3. Campus Area Network (CAN)

CAN is bigger than a LAN but smaller than a MAN. This is a type of computer network that is usually used in places like a school or colleges. This network covers a limited geographical area that is, it spreads across several buildings within the campus. CAN mainly use Ethernet technology with a range from 1km to 5km. Its transmission speed is very high with a moderate maintenance cost and moderate cost. Examples of CAN are networks that cover schools, colleges, buildings, etc.

Advantages of CAN

• Speed: Communication within a CAN takes place over Local Area Network (LAN) so data transfer rate between systems is little bit fast than Internet.
• Security: Network administrators of campus take care of network by continuous monitoring, tracking and limiting access. To protect network from unauthorized access firewall is placed between network and internet.
• Cost effective: With a little effort and maintenance, network works well by providing fast data transfer rate with multi-departmental network access. It can be enabled wirelessly, where wiring and cabling costs can be managed. So to work with in a campus using CAN is cost-effective in view of performance

4. Metropolitan Area Network (MAN) 

A MAN is larger than a LAN but smaller than a WAN. This is the type of computer network that connects computers over a geographical distance through a shared communication path over a city, town, or metropolitan area. This network mainly uses FDDI, CDDI, and ATM as the technology with a range from 5km to 50km. Its transmission speed is average. It is difficult to maintain and it comes with a high cost. Examples of MAN are networking in towns, cities, a single large city, a large area within multiple buildings, etc.

Advantages of MAN

• MAN offers high-speed connectivity in which the speed ranges from 10-100 Mbps.
• The security level in MAN is high and strict as compared to WAN.
• It support to transmit data in both directions concurrently because of dual bus architecture.
• MAN can serve multiple users at a time with the same high-speed internet to all the users.
• MAN allows for centralized management and control of the network, making it easier to monitor and manage network resources and security.

Disadvantages of MAN

• The architecture of MAN is quite complicated hence, it is hard to design and maintain.
• This network is highly expensive because it required the high cost to set up fiber optics.
• It provides less fault tolerance.
• The Data transfer rate in MAN is low when compare to LANs.

5. Wide Area Network (WAN)

WAN is a type of computer network that connects computers over a large geographical distance through a shared communication path. It is not restrained to a single location but extends over many locations. WAN can also be defined as a group of local area networks that communicate with each other with a range above 50km. Here we use Leased-Line & Dial-up technology. Its transmission speed is very low and it comes with very high maintenance and very high cost. The most common example of WAN is the Internet.

Advantages of WAN

• It covers large geographical area which enhances the reach of organisation to transmit data quickly and cheaply.
• The data can be stored in centralised manner because of remote access to data provided by WAN.
• The travel charges that are needed to cover the geographical area of work can be minimised.
• WAN enables a user or organisation to connect with the world very easily and allows to exchange data and do business at global level.

Disadvantages of WAN

• Traffic congestion in Wide Area Network is very high.
• The fault tolerance ability of WAN is very less.
• Noise and error are present in large amount due to multiple connection point.
• The data transfer rate is slow in comparison to LAN because of large distances and high number of connected system within the network.

Comparison between Different Computer Networks

Other Types of Computer Networks

• Wireless Local Area Network (WLAN)
• Storage Area Network (SAN)
• System-Area Network (SAN)
• Passive Optical Local Area Network (POLAN)
• Enterprise Private Network (EPN)
• Virtual Private Network (VPN)
• Home Area Network (HAN)

1. Wireless Local Area Network (WLAN)

WLAN is a type of computer network that acts as a local area network but makes use of wireless network technology like Wi-Fi. This network doesn't allow devices to communicate over physical cables like in LAN but allows devices to communicate wirelessly. The most common example of WLAN is Wi-Fi.

There are several computer networks available; more information is provided below.

2. Storage Area Network (SAN)

SAN is a type of computer network that is high-speed and connects groups of storage devices to several servers. This network does not depend on LAN or WAN. Instead, a SAN moves the storage resources from the network to its high-powered network. A SAN provides access to block-level data storage. Examples of SAN are a network of disks accessed by a network of servers.

3. Passive Optical Local Area Network (POLAN)

A POLAN is a type of computer network that is an alternative to a LAN. POLAN uses optical splitters to split an optical signal from a single strand of single-mode optical fiber to multiple signals to distribute users and devices. In short, POLAN is a point to multipoint LAN architecture. 

4. Enterprise Private Network (EPN)

EPN is a type of computer network mostly used by businesses that want a secure connection over various locations to share computer resources. 

5. Virtual Private Network (VPN)

A VPN is a type of computer network that extends a private network across the internet and lets the user send and receive data as if they were connected to a private network even though they are not. Through a virtual point-to-point connection users can access a private network remotely. VPN protects you from malicious sources by operating as a medium that gives you a protected network connection. 

6. Home Area Network (HAN)

Many of the houses might have more than a computer. To interconnect those computers and with other peripheral devices, a network should be established similar to the local area network (LAN) within that home. Such a type of network that allows a user to interconnect multiple computers and other digital devices within the home is referred to as Home Area Network (HAN). HAN encourages sharing of resources, files, and programs within the network. It supports both wired and wireless communication. 

Internetwork

An internet network is defined as two or more computer network LANs, WANs, or computer network segments that are connected by devices and configured with a local addressing system. The method is known as internetworking. There are two types of Internetwork.

• Intranet: An internal network within an organization that enables employees to share data, collaborate, and access resources. Intranets are not accessible to the public and use private IP addresses.
• Extranet: Extranets extend the intranet to authorized external users, such as business partners or clients. They provide controlled access to specific resources while maintaining security.

Advantages of Computer Network

• Central Storage of Data: Files are stored on a central storage database which helps to easily access and available to everyone.
• Connectivity: A single connection can be routed to connect multiple computing devices.
• Sharing of Files: Files and data can be easily shared among multiple devices which helps in easily communicating among the organization.
• Security through Authorization: Computer Networking provides additional security and protection of information in the system.

Disadvantages of Computer Network

• Virus and Malware: A virus is a program that can infect other programs by modifying them. Viruses and Malware can corrupt the whole network.
• High Cost of Setup: The initial setup of Computer Networking is expensive because it consists of a lot of wires and cables along with the device.
• loss of Information: In case of a System Failure, might lead to some loss of data.
• Management of Network: Management of a Network is somehow complex for a person, it requires training for its proper use.