A database server is a computer system that provides other computers with services related to accessing and retrieving data from a database. Access to the database server may occur via a "front end" running locally a user's machine (e.g., phpMyAdmin), or "back end" running on the database server itself, accessed by remote shell. After the information within the database is retrieved it is outputted to the user requesting the data.
Many companies utilize a database server for storage. Users can access the data by executing a query using a query language specific to the database. For example, SQL is a good example of a query language.