Every day people type domains like "wikipedia.org" into their browser to open websites. Behind every link you click, there is a URL with a domain. But what is actually hidden behind this sequence of letters and the dot of a domain? What does this mean for you as the operator of a website?
Domains function according to the Domain Name System, or DNS for short. In order to understand the connections between domains, servers, IP addresses, registrars and the many security aspects, it is helpful to understand, at least in broad outline, what this internet actually is.
There is no Cloud
The internet - often referred to as "the Cloud" or depicted as a cloud - is not somewhere else, but directly where you are. Every device, whether laptop, tablet, smartphone or server is a computer and becomes part of a network as soon as it is connected to other devices via cable or Wi-Fi. The internet is a large network of smaller networks and is the result of the interaction of computers connected by cable, radio links, routers and data centres.
These places and infrastructures are operated by a wide variety of people and organisations with a wide range of interests - from government or university networks, internet giants such as Google or Facebook, to node operators and data traders, and even illegal "darknet" platforms - all networks use the same principle and together form the internet.
If data is exchanged over the internet between two devices, e.g. a smartphone and a server at dotplex, the data runs over several third-party networks and computers as intermediate stations. Each of the many computers, on which e.g. your website or a chat service runs, has a unique address, comparable to a telephone number.
IP addresses and data packets
These numbers - the IP addresses - appear as receiver and sender on the data packets that are transported through the cables. The addresses are used by all the intermediate stations to decide which route the data packets take through the network from a selection of numerous route options, so that they ultimately arrive at the correct device, e.g. your server at dotplex in Berlin. Such IP addresses are sequences of numbers. However, since humans are better at remembering words than numbers, and since you do not want to expect visitors of your website to type the IP address into their browser, the Domain Name System was put over this IP address system.
Domain Name System (DNS)
The Domain Name System, DNS for short, assigns names (domains) to numbers (IP addresses). This is similar to an address book in a telephone, which is used to avoid having to remember telephone numbers and type them in. The available extensions for domains such as .de, .com or .org are so-called top-level domains, or TLDs for short. They are assigned by institutions ("registries") under various conditions.
The top-level domain ".de", for example, is administered by the non-profit organisation DENIC. The prerequisite for registering a .de domain is that the contact details of a natural person and an address in Germany must be provided. Other domains such as .com (for companies) or .gov (for governments) have different requirements and are administered and assigned by other organisations. However, an individual cannot register a domain such as "example.de" directly with DENIC. Instead, he or she commissions a provider such as dotplex, which usually offers many different TLDs.
Name servers and DNS records
Once you have registered the domain example.de, you become the so-called Admin-C and can decide to which server the domain and the corresponding subdomains such as shop.example.de, mail.example.de or www.beispiel.de should point to, i.e. which IP address is stored for the domain. The list of domain to IP address assignments is managed by so-called name servers.
Individual entries of such a list are called DNS records or simply records and can contain other information besides the assignment of IP addresses to a domain. A records stand for the assignment of a domain or sub-domain to IPv4 addresses and AAAA records to IPv6 addresses. The MX record allows you to specify the server to which the e-mails for a domain are delivered.
As with telephone directories, where there is a copy for each region, the Domain Name System has a large number of name servers. As Admin-C of example.de, you can set at your registrar on which name server the information that should apply to your domain is located.
How a browser finds your server via DNS
If a person now enters your domain "example.de" in the browser, the browser queries the hierarchically organised name servers one after the other, starting with the root name servers, which point to the name servers responsible for the top-level domain .de. In general, DENIC's name servers in turn point to the name servers of your provider, where the IP addresses for the domain are stored. In order to simplify and speed up these queries, however, the browser usually simply uses the name server of the internet provider that takes over and temporarily stores the recursive queries. Once the browser has finally received the IP address for example.de, it can retrieve the website from the correct server.
One-stop shop domain administration
The internet is decentralised for good reason, and many are working at various levels to ensure the continued existence of an independent internet. However, when it comes to setting up websites, the distributed organisation can be a logistical challenge and lead to delays or even longer downtimes if not all steps are coordinated.
dotplex operates its own name servers and we can register domains of almost all top-level domains for you. This means that we can guarantee the configuration of your domains, including SSL certificates, from a single source and without any downtime for your website or e-mails. Of course, we are also happy to advise you on the setup of external domains and the use of external name servers.
More about domains
Also read on why the Domain Name System (DNS) is fundamentally insecure and how dotplex secures your domains and protects visitors to your website with best practice measures such as HTTPs, DNSSEC and DANE.