What is Networking? Different Types of Networks in Computer Explained

Networking refers to two or more interconnected computing devices exchanging data or sharing resources. This network of multiple computer systems is connected through physical or wireless technologies, such as a router or server. Also, the connected devices follow a set of rules known as communication protocols to transmit information. 

In this write-up (part of the complete Ethical Hacking Tutorial for beginners), let’s discuss what is networking in computers and IT, core concepts related to it, different types of networks, and much more.

Before diving into the details of networking in ethical hacking, let’s understand what is ethical hacking. It is the process of scanning connected systems to scan vulnerabilities and identify potential threats and risks to a computer system or network. An ethical hacker is responsible for finding loopholes in an app, system, or network, and reporting the same to the employer or team manager. 

One of the critical factors in ethical hacking is networking. 

The meaning of networking is multiple interconnected devices, known as hosts, that are connected using several paths to share or receive data. A fair understanding of networks, such as Subnetting, DHCP, Suoernetting, etc., enables ethical hackers to assess the connected devices, determine potential security risks, and eliminate those threats. 

Now that we know what is networking in computer and how does it work, as well as discussed the core concepts, it is time to know about the different types of networks. 

1. Local Area Network (LAN)

It is the network of connected devices in a physical location, like an office, home, or other building. The size of a LAN can be small or large, depending on where it is used. The point worth noting is that the network will be in a limited area. 

2. Metropolitan Area Network (MAN)

MAN is the network of connected devices within a large area, like a big city. It is bigger than the LAN network as it connects devices in multiple buildings within a metropolitan area. 

The term ‘metropolitan’ here describes the size of the area a MAN can cover. If a city or town is small, it can cover multiple nearby cities or towns. 

3. Wide Area Network (WAN)

WAN is an extensive network of devices that connects numerous devices from multiple buildings, cities, or regions. 

Large organizations and enterprises with multiple branches, remote employees, suppliers, etc., use this network.

Hope the above definition of networking in computer helped you understand the concept easily. Now, we will talk about some of the most important networking terms and concepts. 

1. IP Address and Types

Every device has a unique IP (Internet Protocol) address used to recognize a device in a network. 

Using an IP address, you can identify the device and its location, and use it for sharing information on a network. 

Here is an example of an IP address: 112.196.166.43

Here are the different types of IP addresses in networking:

• Private IP Address

Private IP addresses are unique addresses for each device in a network. For instance, if there are several laptops, smartphones, desktops, etc., in an office connected to a router, each device will have a private IP address. 

Bluetooth-based devices like speakers, smart TVs, printers, etc., also have private IP addresses. 

• Public IP Address

The public IP address is assigned to an entire network, meaning that all the network devices have the same IP address. Usually, the public IP address is delivered by the Internet Service Provider (ISP) to a router. 

• Static IP Address

The IP address that remains unchanged for years is known as a static IP address. These can’t be changed once assigned unless there is a change in routine network administration. 

• Dynamic IP Address

Dynamic IP addresses work opposite to static ones and keep changing. Generally, a dynamic IP address is assigned temporarily to a device using DHCP (Dynamic Host Configuration Protocol) or PPPoE (Point to Point Protocol over Ethernet).

2. Networking Ports

A port is a virtual place at the software level in an operating system that is used to identify the types of network services. It is where the connection with a network begins and ends. 

All ports have their unique process. The role of ports in a computer is to identify the type of traffic from the network. For example, the emails sent or received on a device use a different port than a website accessed through browsers, even when the internet connection is the same.

3. OSI Model (Open Systems Interconnection)

The OSI model is a standard and conceptual model for computers and devices used to connect with other computers and devices. The communication between devices follows a standard protocol. 

Created by ISO (International Organization for Standardization), the OSI model divides the communication between systems into seven different layers. Every layer's role is different and connected to the layers above and below it. 

Ethical hackers and professionals refer to these layer names when mentioning the relevant functionalities of the Open Systems Interconnection.

4. TCP/IP Model

The full form of TCP/IP is Transmission Control Protocol/Internet Protocol. This model is quite similar to the OSI model but is based on standard protocols. After learning what is computer networking, you should have a clear idea of the TCP/IP model.

It is because when we talk about network communications, it is the most used model. Its role is to enable end-to-end data transmission. 

The architecture of the TCP/IP model is more straightforward than the OSI model, as it has only four layers. Created by the Department of Defence (DoD), the TCP/IP model can be called a concise version of the OSI model.

5. TCP (Transmission Control Protocol)

TCP is a standard protocol to define the ways for creating and managing the connections between devices in a network to exchange packets of data. It maintains the connection to ensure the data is exchanged between the devices. 

This protocol also solves several challenges related to packet-based messaging. These challenges can be out-of-order packets, duplicate packets, corrupted packets, etc. TCP works with the Internet Protocol (IP).

6. UDP (User Datagram Protocol)

UDP in networking stands for User Datagram Protocol). It is an alternative to TCP. It is a communication protocol used to exchange data between the devices in a network. UDP is especially meant for the transmission of time-sensitive files. So, it transfers the data faster than TCP but is not as reliable as TCP. 

To enable faster data transfer, it avoids factors like the handshake, doesn’t check whether the data is transmitted properly, and if some data is lost while transmitting, it will not resume. Hence, it accelerates transmission speed but doesn’t guarantee successful data transfer. 

User Datagram Protocol is used for time-bound tasks where it is better to drop the packets of data instead of waiting. Generally, it is preferred for video playbacks, voice traffic, and DNS lookups.

7. ICMP (Internet Control Message Protocol)

ICMP in networking stands for Internet Control Message Protocol. It is a network layer protocol used in the devices within a network to find whether the data transmission initiated by a device has reached the destination without fail. 

After knowing what is networking in computer, you must know that the key role of ICMP is to report the errors in communication in a network. Mostly, it is used in routers, hosts, and intermediary devices within the network.

For example, if a packet of data is transmitted from source to destination, but the router finds this packet too large to process, then the data will be dropped, and an ICMP message will be sent to the source that the data couldn’t be transmitted.

8. DNS (Domain Name System)

DNS is the Domain Name System on the internet that converts domain names into IP addresses. Domain names are user-friendly, but machines and servers need IP addresses for processing user requests. So, DNS converts a domain name like microsoft.com into an IP address like 192.7.0.34. 

DNS is often called the phonebook of the internet because it stores the domain names of the websites with their IP addresses, the same way phonebooks store the names of the people with their phone numbers.

9. HTTP Request

The request made by the client to a host on the server to access the resources on the server is known as an HTTP request. 

URL components are required to place an HTTP request.

10. HTTP Response

When the server responds to the HTTP request of the client, it is called an HTTP response. Here, the server delivers the resources requested by the client or informs about the errors in fetching the resources.

11. IP Address vs MAC Address

After knowing what is networking on the computer, you will always come across the concepts of IP address and Mac address. Understand the difference between the two below.

An IP address is a unique address assigned to every device. It consists of numbers and is used to track the location of a system connected to the internet.

MAC (media access control) address is a unique identifier assigned to every device connected to the network. It is found on a device's network interface card (NIC).