How the Internet Works

How the Internet Works

Featuring packets, TCP/IP, DNS, SSL/TLS, and other building blocks of the Internet

In this article, we'll delve into the step-by-step layers that constitute the internet. Our focus here will be on comprehending the technical concepts that underpin each activity that takes place on the internet.

To begin, the Internet is essentially a network of interconnected devices and computer systems, all operating under a standard protocol or set of rules. It serves as the primary infrastructure that enables devices located in different regions to connect, share information, and communicate with one another.

These systems and devices are linked through wired cables, with fiber optic cables being the predominant choice due to their efficiency in transmitting data through light. Consequently, messages can traverse these systems at the speed of light. However, in efforts to reduce costs and fulfill the growing demand for faster connections, radio waves are predominantly employed to facilitate wireless and expedited connections.

Information Transmission through Packets

The information and messages shared over the internet are transmitted in the form of discrete units known as packets. A packet represents the smallest unit of information, consisting of 1s and 0s. For instance, when someone sends a message such as 'Hello World' or transmits an image, the message is divided into packets, which are subsequently transmitted to the recipients in a sequential manner. This transmission adheres to a standardized protocol to ensure the secure delivery of these packets to the intended recipient. The packets primarily contain the IP address of the destination, the IP address of the source, and the payload, which constitutes the core message.

The Protocols Driving Internet Communication

The fundamental protocols responsible for the core transmission of information across the Internet are the Internet Protocol (IP) and the Transmission Control Protocol (TCP).

IP is an essential protocol that provides the addressing and routing mechanisms necessary for data packets to travel from the source to their intended destination. While it is often considered unreliable and connectionless, it forms the foundation of the Internet's packet-switched network. IP's primary role is to forward packets to their destination, without being overly concerned about whether they reach their intended target or not.

On the other hand, TCP functions as a reliable connection protocol. It ensures that all sent packets reach their destination securely and in the correct order. In cases where there is a disruption in packet transmission, TCP communicates with the sender to request the retransmission of missing packets, thereby ensuring their delivery.

For example, when streaming a video, the server transmits the video as a series of packets. TCP plays a crucial role in ensuring that these packets are sent and properly arranged, maintaining a seamless streaming experience. In cases of service interruptions that hinder effective packet transfer, TCP communicates with the server to request the retransmission of missing packets.

IP Address and Domain Name

The IP/TCP protocols can only guarantee the delivery of packets to the correct recipients by knowing the recipients' addresses. These addresses are in the form of IP addresses, which are unique identifiers for every device and system communicating over the internet.

IP addresses are structured as four sets of numbers separated by dots, resembling nnnn.nnnn.nnnn.nnn, where 'n' represents a number. However, these addresses are not human-readable or easily memorized. This is why domain names are assigned to each IP address on the internet.

For example, '' is a domain name for Google's IP address. And to communicate with the Google server, you only need to know the domain name. You can enter this domain name into a web browser to access the desired information. Behind the scenes, TCP collaborates with the IP address, sending it along with the packets to guarantee they reach their intended recipient.

Domain Name System (DNS)

The management of domain names for each server is overseen by the Domain Name System (DNS), which functions as the internet's equivalent of a phone book. Its primary role is to translate domain names into IP addresses. To ensure a sustainable source of unique domain names and IP addresses, a domain definition system called IPv6 was introduced.


When a client, such as a mobile phone, attempts to search for something on, the message is sent following a standard structure known as HTTP, which stands for Hypertext Transfer Protocol. It is the protocol used for transmitting documents like HTML between the client and a server.

HTTP serves as the foundation for any data exchange on the Web and operates as a client-server protocol, with requests typically initiated by the recipient, often the web browser.

However, HTTP transmits data in plain text, making it vulnerable to interception and potential information corruption or theft. For instance, sensitive data like credit card information entered into form fields can be intercepted and stolen. This is why we have HTTPS, the encrypted and secure version of HTTP, with the 'S' at the end signifying security

Securing Internet Communication with HTTPS

How can we ensure that information transmitted over the internet remains secure and protected? This is where SSL (Secure Sockets Layer) and TLS (Transport Layer Security) come into play. Both SSL and TLS are used to enhance internet communication through HTTPS, guaranteeing the security of the information exchanged.

The way they function is by encrypting the messages sent from a client to the server using specific algorithms and a private key obtained from the server. This private key is utilized on the server to decrypt the message upon arrival. Any potential interceptor will only observe the encrypted message, which cannot be decrypted without the key from the server. This is the fundamental mechanism behind securing Internet communications.


Everyone who uses the internet should have at least a basic understanding of how it works. In this article, we've simplified the complexities around it. We have learned that:

  • The Internet is a network of various systems.

  • Information and messages are transmitted in the form of packets.

  • IP and TCP are the transmission protocols that ensure the proper routing and delivery of packets from source to destination.

  • The IP address serves as the unique identifier for each system, while domain names act as aliases for human readability.

  • The Domain Name System (DNS) functions as the internet's phone book, linking domain names with IP addresses.

  • HTTP is the standard format for communication on the web, and HTTPS is its secure version designed to prevent vulnerabilities.

  • SSL and TLS are the mechanisms used by HTTPS to secure internet communication.

Further Learning

  1. How does the internet work?

  2. SSL, TLS, HTTPS Explained - YouTube

  3. How does the Internet Work? -

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