This is how the Internet works: The most important things simply explained

The use of the Internet is now an integral part of everyday life. But how does the network of networks actually work? In our article, we investigate this question and explain the most important functional principles on the Internet.

What is the internet?

Put simply, the Internet is a network of many computer networks that exchange data with each other and thus enable the use of various services such as email or the WWW. This is commonly referred to as surfing. The Internet has grown historically from the Arpanet of the United States Department of Defense, which was created in the late 1960s. The aim was to make sensible use of the capacities of several mainframes and to connect universities and research institutions.

• The lynchpin for data exchange and thus an important part of the Internet are the Internet nodes. These are distributed all over the world and pass data on to each other. As a rule, several, sometimes hundreds, service providers - also called providers - are connected to an Internet node. Data is exchanged between the providers within the network node. Measured by the amount of data traffic, the world's largest Internet node is located in Frankfurt am Main, where it is distributed across around 19 data centers.
• The providers in turn enable their customers, such as companies or private households, to access the Internet by providing appropriate connections such as DSL or LTE.
• Many companies operate their own networks, called intranets, which become part of the Internet when the connection to the provider is established. While private individuals are mostly only users and call up information or services, many companies offer Internet services themselves. In addition to the general provision of information, this includes, for example, online shops, cloud storage or booking portals.
• The actual data transmission between the Internet nodes and the providers takes place worldwide via fiber optic cables, which enable high transmission speeds. The connection of households or companies, also known as the last mile, is usually realized by copper cable, radio and increasingly also by fiber optics. To ensure that everything runs smoothly, the type of data exchange is regulated via so-called protocols.
• The Internet protocol family, for example, stipulates that the data to be transmitted is broken down into small packets by the sender, then transmitted and reassembled by the recipient.
• So that a data packet knows where it comes from and where it has to be sent, each computer involved in the communication receives a unique address, the IP address. This consists of four blocks of numbers separated by dots. Since hardly anyone can remember the IP addresses of the websites visited or other services, there is the Domain Name System (DNS). This means that, instead of IP addresses, descriptive names can be used for websites, strictly speaking, Internet servers. You know this as Internet addresses, www addresses or URL.

What happens when I go to a website?

Calling up a website is just one of countless use cases on the Internet. This example can be used to explain how communication on the Internet works. That is the basic principle of how the Internet works.

• If you enter a URL in the browser, such as www.chip.de, pressing the Enter key will send a request to your provider. First, it does the name resolution, i.e. the conversion of the name into the IP address of the target server. The target server is the server on which the website you are looking for is stored.
• The provider uses one or more special servers for name resolution. They are called DNS servers because they only have one task. Simply put, DNS servers maintain a directory with all websites and the associated IP addresses like a dictionary.
• Once the IP address of the target server has been determined, the request is forwarded via the Internet node to the web server on which the page you are looking for is located. Since the Internet spans the world like a spider web, there are also different ways that the data packets can take. In order to find the optimal route, all networks are connected to each other with routers. A router accepts data packets and then decides where to forward them to.
• After the request has reached its destination, the server replies and returns the content of the website. You must now find the way to your computer from which you made the request. For this to work, the data packets not only contain recipient information, but also the sender's IP address. The procedure is the same: the response packets move from network to network via the router and finally reach your computer. There they are put together and the searched website is displayed in the browser.

If you want to create your own homepage, the next article is interesting for you. We give you important tips and introduce you to good providers.