What are the types of computer network?

What are the types of computer network?

First, What is a Computer Network?

A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is connection to the Internet. Other shared resources can include a printer or a file server. The Internet itself can be considered a computer network.(source: https://study.com/academy/lesson/what-is-a-computer-network-types-definition-quiz.html)

4 Types of Computer Network 

Personal Area Network (PAN)
-is a computer network used for data transmission amongst devices such as computers, telephones, printers, etc. 

• - it is also the interconnection of information technology devices within the range of an individual person, typically within a range of 10 meters. For example, a person traveling with a laptop, a personal digital assistant (PDA), and a portable printer could interconnect them without having to plug anything in, using some form of wireless technology. Typically, this kind of personal area network could also be interconnected without wires to the Internet or other networks. Also see wireless personal area network (WPAN) which is virtually a synonym since almost any personal area network would need to function wirelessly. Conceptually, the difference between a PAN and a wireless LAN is that the former tends to be centered around one person while the latter is a local area network (LAN) that is connected without wires and serving multiple users.

•  In another usage, a personal area network (PAN) is a technology that could enable wearable computer devices to communicate with other nearby computers and exchange digital information using the electrical conductivity of the human body as a data network. For example, two people each wearing business card-size transmitters and receivers conceivably could exchange information by shaking hands. The transference of data through in
  
  
  tra-body contact, such as handshakes, is known as linkup. The human body's natural salinity makes it a good conductor of electricity. An electric field passes tiny currents, known as Pico amps, through the body when the two people shake hands. The handshake completes an electric circuit and each person's data, such as e-mail addresses and phone numbers, are transferred to the other person's laptop computer or a similar device. A person's clothing also could act as a mechanism for transferring this data. (source:https://searchmobilecomputing.techtarget.com/definition/personal-area-network) 

Local Area Network (LAN)
- is a computer network that spans a relatively small area.

• Stands for "Local Area Network" and is pronounced "lan." A LAN is a network of connected devices that exist within a specific location. LANs may be found in homes, offices, educational institution, or other areas.
  A LAN may be wired, wireless, or a combination of the two. A standard wired LAN uses Ethernet to connect devices together. Wireless LANs are typically created using a Wi-Fi signal. If a router supports both Ethernet and Wi-Fi connections, it can be used to create a LAN with both wired and wireless devices.

 Types of LANs

Most residential LANs use a single router to create the network and manage all the connected devices. The router acts as the central connection point and enables devices, such as computers, tablets, and smartphones to communicate with each other. Typically, the router is connected to a cable or DSL modem, which provides Internet access to connected devices.

A computer may also be the central access point of a LAN. In this setup, the computer acts as a server, providing connected machines with access to files and programs located on the server. It also includes LAN software used to manage the network and connected devices. LAN servers are more common in business and educational networks, since the extra capabilities are not required by most home users. In a server-based LAN, devices may connect directly to the server or indirectly via a router or switch.(source: https://techterms.com/definition/lan)

Metropolitan Area Network (MAN)
- it involves connecting several networks together that reside with a city, town or metropolis.

-A metropolitan area network (MAN) is similar to a local area network (LAN) but spans an entire city or campus. MANs are formed by connecting multiple LANs. Thus, MANs are larger than LANs but smaller than wide area networks (WAN). 

-MANs are extremely efficient and provide fast communication via high-speed carriers, such as fiber optic cables.

-A MAN is ideal for many kinds of network users because it is a medium-size network. MANs are used to build networks with high data connection speeds for cities and towns. 

-The working mechanism of a MAN is similar to an Internet Service Provider (ISP), but a MAN is not owned by a single organization. Like a WAN, a MAN provides shared network connections to its users. A MAN mostly works on the data link layer, which is Layer 2 of the Open Systems Interconnection (OSI) model. 

Distributed Queue Dual Bus (DQDB) is the MAN standard specified by the Institute Of Electrical And Electronics Engineers (IEEE) as IEEE 802.6. Using this standard, a MAN extends up to 30-40 km, or 20-25 miles. (source: https://www.techopedia.com/definition/8238/metropolitan-area-network-man)

Wide Area Network (WAN)

-is a geographically distributed private telecommunications network that interconnects multiple area network.

-A WAN (wide area network) is a communications network that spans a large geographic area such as across cities, states, or countries. They can be private to connect parts of a business or they can be more public to connect smaller networks together.

The easiest way to understand what a WAN is to think of the internet as a whole, which is the world's largest WAN. The internet is a WAN because, through the use of ISPs, it connects lots of smaller local area networks (LANs) or metro area networks (MANs).

On a smaller scale, a business may have a WAN that's comprised of cloud services, its headquarters, and smaller branch offices. The WAN, in this case, would be used to connect all of those sections of the business together.

No matter what the WAN joins together or how far apart the networks are, the end result is always intended to allow different smaller networks from different locations to communicate with one another.

-How WANs Are Connected

Since WANs, by definition, cover a larger distance than LANs, it makes sense to connect the various parts of the WAN using a virtual private network (VPN). This provides protected communications between sites, which is necessary given that the data transfers are happening over the internet.

Although VPNs provide reasonable levels of security for business uses, a public internet connection does not always provide the predictable levels of performance that a dedicated WAN link can. This is why fiber optic cables are sometimes used to facilitate communication between the WAN links.(source: https://www.lifewire.com/wide-area-network-816383)

                           

Internet was invented by Tim Berners-Lee in 1989.

• Interestingly, Microsoft is ahead of Google in terms of number of servers owned. Microsoft has over one million servers whereas Google has 900,000.
• According to Google, Internet contains 5 million Terabytes of data. Google’s search index is about 0.004% of this.
• Now about 3 billion people are connected to Internet. World’s total population is about 7 billion.
• QWERTY keyboard sequence is 129 years old.
• First ever microprocessor by Intel was “4004”
• First Computer Company to register domain name was “Digital Equipment Corporation”
• Micral N was the first personal computer built on Intel processor 8008. This personal computer was built in 1972 and more than 90,000 units were sold
• Six main Internet cable landing stations are located in Tokyo, Singapore, New York, Cornwell, Southern Florida and Hong Kong.

• In 2008, Internet was controlled by 30 million servers. Now this number is nearly 75 million.

Source: Google