A domain name is an identification string that defines a domain of administrative autonomy, authority or control on the internet. In simple terms, an internet domain is a unique name that defines "something" on the internet. This "something" can be a server, a web page, an application, etc. (for example, something.mydomain.org). A domain name generally identifies a zone, an organisation, or a server computer that hosts a website or the website itself.
The primary purpose of the domain name system (DNS) is to facilitate access to resources. The most common resource is the translation between understandable and easy-to-remember names (http://www.pangea.org/) and the IP address of the resource on the internet (109.69.8.145).
From a less technical point of view, a domain name is your name on the internet; it serves to identify you uniquely and unequivocally. It allows you to identify all your services on the internet (in your web pages, email addresses, distribution lists, or other applications that you can use on the internet) under the same name (something.mydomain.org). This domain name gives you an "identity" and allows internet users to communicate with you easily and conveniently. Thus, it is recommended that the domain name you choose has to do with the name of your entity, your project... so that the relationship is clear, that it be easy to write and memorise and that it be as short as possible, among other things.
This user-friendly guide from Pangea provides an overview of everything you need to know to choose a domain name, with plain-language explanations of all the factors involved, including the "syntax" of a domain name, top-level domains, second-level and lower-level domains, and management and maintenance.
This guide was produced with the support of the Association for Progressive Communications (APC) through a subgrant made possible by the Swedish International Development Cooperation Agency (Sida).