It’s no secret that more and more the internet is becoming an integral part of our everyday lives. But if you are new to the online experience, it may be a bit overwhelming. You may be wondering, “What exactly is the internet, and how does it work?”
The Internet:
In the early days, most people just used the internet to search for information. Today’s internet is a constantly evolving tool, that not only contains an amazing variety of information but also provides new ways of accessing, interacting, and connecting with people and content. As a result, new terms are constantly appearing as new technologies are introduced.
What is the Internet?
The internet is the largest computer network in the world, connecting millions of computers. A network is a group of two or more computer systems linked together.
Computer Networks
We are living in a connected world. Information is being produced, exchanged, and traced across the globe in real-time. It’s possible as almost everyone and everything in the digital world is interconnected in one way or the other.
A group of two or more similar things or people interconnected with each other is called a network. Some of the examples of the network in our everyday life include:
- Social network
- Mobile network
- Network of computers
- Airlines, railways, banks, hospitals networks
A computer network is an interconnection among two or more computers or computing devices. Such interconnection allows computers to share data and resources with each other. A basic network may connect a few computers placed in a room.
The network size may vary from small to large depending on the number of computers it connects. A computer network can include different types of hosts (also called nodes) like servers, desktops, laptops, and cellular phones.
Apart from computers, networks include networking devices like switches, routers, modems, etc. Networking devices are used to connect multiple computers in different settings. For communication, data in a network is divided into smaller chunks called packets. These packets are then carried over a network. Devices in a network can be connected either through wired media like cables or wireless media like air. In a communication network, each device that is a part of a network and that can receive, create, store or send data to different network routes is called a node. In the context of data communication, a node can be a device such as a modem, hub, bridge, switch, router, digital telephone handset, a printer, a computer, or a server.
Evolution of Networking
In the 1960s a research project was commissioned by the Advanced Research Projects Agency Network (ARPANET) in the U.S. Department of Defence to connect the academic and research institutions located at different places for scientific collaborations. The first message was communicated between the University of California, Los Angeles (UCLA) and the Stanford Research Institute (SRI). Slowly but gradually, more and more organizations joined the ARPANET, and many independent smaller networks were formed. Few of the milestones in the magnificent journey of evolution of computer networks are depicted in the timeline.
Types of Networks
There are various types of computer networks ranging from networks of handheld devices (like mobile phones or tablets) connected through Wi-Fi or Bluetooth within a single room to the millions of computers spread across the globe. Some are connected wireless while others are connected through wires. Based on the geographical area covered and data transfer rate, computer networks are broadly categorised as:
- PAN ( Personal Area Network)
- LAN (Local Area Network)
- MAN (Metropolitan Area Network)
- WAN (Wide Area Network)
1. Personal Area Network (PAN)
It is a network formed by connecting a few personal devices like computers, laptops, mobile phones, smartphones, printers, etc. All these devices lie within an approximate range of 10 meters. A personal area network may be wired or wireless. For example, a mobile phone connected to the laptop through USB forms a wired PAN while two smartphones communicating with each other through Bluetooth technology form a wireless PAN or WPAN.
2. Local Area Network (LAN)
It is a network that connects computers, mobile phones, tablets, mouce, printers, etc., placed at a limited distance. The geographical area covered by a LAN can range from a single room, a floor, or an office having one or more buildings on the same premise, laboratory, a school, college, or university campus. The connectivity is done by means of wires, Ethernet cables, fiber optics, or Wi-Fi.
LAN is comparatively secure as only authentic users in the network can access other computers or shared resources. Users can print documents using a connected printer, and upload/download documents, and software to and from the local server. Such LANs provide short-range communication with high-speed data transfer rates. These types of networks can be extended up to 1 km. Data transfer in LAN is quite high and usually varies from 10 Mbps (called Ethernet) to 1000 Mbps (called Gigabit Ethernet), where Mbps stands for Megabits per second. Ethernet is a set of rules that decides how computers and other devices connect
with each other through cables in a local area network or LAN.
3. Metropolitan Area Network (MAN)
Metropolitan Area Network (MAN) is an extended form of LAN which covers a larger geographical area like a city or a town. Data transfer rate in MAN also ranges in Mbps, but it is considerably less as compared to LAN. Cable TV networks or cable-based broadband internet services are examples of MAN. This kind of network can be extended up to 30-40 km. Sometimes, many LANs are connected together to form MAN.
4. Wide Area Network (WAN)
Wide Area Network connects computers and other LANs and MANs, which are spread across different geographical locations of a country or in different countries or continents. A WAN could be formed by connecting a LAN to other LANs via wired/wireless media. Large business, educational, and government organizations connect their different branches in different locations across the world through WAN. The Internet is the largest WAN that connects billions of computers, smartphones, and millions of LANs from different continents.
Other Networks:
Apart from the above types of networks, some other important types of networks are as follows:
- Wireless Local Area Network(WLAN)
- System Area Network (SAN)
- Storage Area Network (Also known as SAN)
- Home Area Network (HAN)
- Passive Optical Local Area Network (POLAN)
- Computer Area Network (CAN)
- Enterprise Private Network (EPN)
- Virtual Private Network (VPN)