Explained: Internet

The internet is a vast and complex network that connects billions of devices around the world. It is a global system of interconnected computer networks that use standardized communication protocols to link devices and share information and resources. But how exactly does the internet work?

In this article, we will explore the basics of how the internet functions and the key technologies that make it possible.

At the core of the internet is the Internet Protocol (IP), which is the standard that governs how data is transmitted between devices. IP is responsible for routing data packets from one device to another, and it is the foundation of all internet communication. When a user wants to access a webpage, for example, their device sends a request to a server using IP. The server then sends the requested information back to the user’s device, which displays the webpage. This process happens rapidly and allows for the easy sharing of information and resources across the globe.

Another key technology that powers the internet is the Transmission Control Protocol (TCP). TCP is responsible for ensuring that data packets are delivered reliably and in the correct order. It works by dividing the data into small packets and sending them over the network. If a packet is lost or arrives out of order, TCP will automatically resend it to ensure that the information is delivered correctly.

Another important technology that underpins the internet is the Domain Name System (DNS). DNS is like a phonebook for the internet, it translates human-friendly domain names (like www.example.com) into IP addresses (like 192.0.2.1) that computers can understand. This allows users to easily access websites and other online resources by typing in a simple address rather than having to remember a string of numbers.

The internet also relies on a network of routers, which are devices that direct traffic between different networks. Routers use routing tables to determine the best path for data packets to travel, and they help to ensure that data is delivered quickly and efficiently.

Finally, the internet is made possible by the physical infrastructure that connects devices and networks. This infrastructure includes undersea cables, satellite links, and terrestrial fiber-optic networks that transmit data across the globe.

What is HTTP?

HTTP (Hypertext Transfer Protocol) is a set of rules and standards that govern how data is transmitted over the internet. It is the foundation of the World Wide Web (WWW) and is used to transfer data between web browsers and servers. In this article, we will explore the basics of HTTP and how it works.

HTTP is a request-response protocol, which means that a client (such as a web browser) sends a request to a server, and the server responds with the requested information. When a user types a URL (Uniform Resource Locator) into their web browser, the browser sends an HTTP request to the server where the website is hosted. The server then sends back an HTTP response, which includes the requested webpage and other information.

One of the key features of HTTP is its ability to handle different types of requests. The most common types of HTTP requests are GET and POST. A GET request is used to retrieve information from a server, while a POST request is used to send information to a server.

Another important aspect of HTTP is the use of status codes. These codes are sent back in the HTTP response and indicate the status of the request. The most common status codes include 200 (OK), 404 (Not Found), and 500 (Internal Server Error). These codes provide information about the success or failure of the request and allow web developers to troubleshoot and fix any issues that may arise.

HTTP is also designed to be extensible and can be used in conjunction with other protocols, such as HTTPS (HTTP Secure), which adds an extra layer of security to protect sensitive information during transmission.

Browsers

Browsers, also known as web browsers, are software applications that allow users to access, navigate and view the World Wide Web. They are the primary means by which most people interact with the internet. In this article, we will explore the basics of browsers and how they work.

A browser is essentially a client-side application that runs on a user’s device (such as a computer or mobile device) and interacts with web servers to retrieve and display web pages. When a user types a URL (Uniform Resource Locator) into the address bar of a browser, the browser sends an HTTP (Hypertext Transfer Protocol) request to the server where the website is hosted. The server then sends back an HTTP response, which includes the requested webpage and other information.

One of the key features of browsers is their ability to interpret and display HTML (Hypertext Markup Language), the standard language used to create web pages. HTML is a markup language that provides a structure and layout for a webpage, and browsers use built-in rendering engines to interpret and display this information.

Another important aspect of browsers is their ability to handle different types of web content, such as images, video, and audio. Browsers use built-in plug-ins or extensions to handle different types of media and display them in the browser window.

Browsers also have a variety of features and tools that make it easy for users to navigate and interact with the web. These include bookmarks, history, and tabbed browsing, which allow users to easily save and access their favorite websites and switch between multiple pages.

Another important aspect of browsers is its ability to execute JavaScript, a programming language that can be used to add interactive elements and dynamic functionality to web pages. This makes it possible for web pages to respond to user input, update in real-time, and communicate with other web pages.

DNS

DNS (Domain Name System) is an essential component of the internet that is responsible for translating human-friendly domain names (like www.example.com) into IP addresses (like 192.0.2.1) that computers can understand. In this article, we will explore the basics of DNS and how it works.

When a user types a domain name into their web browser, the browser sends a request to a DNS server to resolve the domain name into an IP address. The DNS server then looks up the IP address associated with that domain name in its database and returns it to the browser. The browser then uses the IP address to connect to the appropriate web server and retrieve the requested webpage.

The process of resolving a domain name into an IP address is known as DNS resolution. It is a hierarchical process that involves a series of DNS servers working together to resolve the domain name. The process starts with a local DNS resolver, which is a DNS server that is typically provided by an internet service provider (ISP).

The local DNS resolver first checks its cache to see if it has recently resolved the domain name in question. If it has, it returns the IP address to the browser without needing to query any other servers. If it doesn’t have the information in its cache, it sends a request to a root DNS server.

The root DNS server is responsible for directing the request to the appropriate top-level domain (TLD) server, such as .com or .org. The TLD server then directs the request to the appropriate authoritative DNS server, which is responsible for managing the domain in question. The authoritative DNS server then returns the IP address associated with the domain name to the local DNS resolver, which in turn returns it to the browser.

DNS is a distributed system and it doesn’t rely on any single server or point of failure. This means that if one DNS server goes down, another server can take over and continue providing DNS resolution services.

Domain Name

A domain name is a human-friendly address that is used to identify and locate resources on the internet, such as websites. It is a unique string of characters that is associated with an IP address, which is a numerical label assigned to each device connected to the internet.

A domain name consists of two parts: the top-level domain (TLD) and the second-level domain (SLD). The TLD is the portion of the domain name that appears at the end, such as .com, .org, .edu, etc. The SLD is the portion that appears before the TLD and can be chosen by the owner of the domain. For example, in the domain name www.example.com, “example” is the SLD and “.com” is the TLD.

Domain names are used to make it easier for users to remember and find websites, rather than having to remember a string of numbers (IP addresses). They are registered and managed by organizations called registrars, which are accredited by the Internet Corporation for Assigned Names and Numbers (ICANN). Users can register a domain name for a fee, and they are required to renew the registration periodically.

Hosting

Web hosting refers to the service of providing storage space and access for websites on servers that are connected to the internet. Hosting companies operate large data centers that contain thousands of servers, and they rent out space on these servers to individuals and organizations that want to host their websites.

When a website is hosted, its files (such as HTML, CSS, JavaScript, and images) are stored on a server, and the server makes them available to users via the internet. When a user types a domain name into their web browser, the browser sends an HTTP request to the server where the website is hosted. The server then returns the requested files, and the browser renders the website for the user to view.

There are different types of hosting services available, including:

• Shared hosting: multiple websites are hosted on the same server and share the same resources. This is the most economical option and is suitable for small to medium-sized websites.
• Virtual Private Server (VPS) hosting: a virtual server is created on a physical server, and the user has full control over the virtual server. This is a more expensive option than shared hosting, but offers more flexibility and control.
• Dedicated hosting: the user rents an entire physical server and has full control over it. This is the most expensive option and is suitable for large, high-traffic websites.
• Cloud hosting: instead of a physical server, the website is hosted on a virtualized environment that is spread across multiple servers. This offers scalability and flexibility, and the user only pays for the resources they use.