Query language is a kind of computer language, which is used for requesting information from database or other information systems.

The request is made via queries, a kind of expression or instruction based on the same principle, so that the user achieves a specified set of objects without the need for specific programming skills. The queries are build as strings with specific keywords and syntax, which vary across the query language.

In general, a distinction is made between database query languages and information retrieval query languages. The best known database query languages are Structured Query Language (SQL), Multidimensional Expression (MDX) and so on. The information retrieval query languages, for instance XQuery, are used for requesting collections of XML data.