A query language is a type of programming language used to make requests for data from databases. It allows users to retrieve, update, and manipulate data in a structured way. Common examples of query languages include SQL (Structured Query Language) for relational databases and SPARQL for querying RDF data. These languages provide a standardized way to interact with data, making it easier for developers and analysts to extract meaningful information. By using specific syntax and commands, users can perform complex searches and operations without needing to understand the underlying database structure.