A query language is a formal computer language used to request information from databases, knowledge bases, or information retrieval systems. Database query languages typically seek precise factual results, while information retrieval query languages often seek relevant documents or records.
Query languages or data query languages (DQLs) are computer languages used to make queries in databases and information systems. Broadly, query languages can be classified according to whether they are database query languages or information retrieval query languages. The difference is that a database query language attempts to give factual answers to factual questions, while an information retrieval query language attempts to find documents containing information that is relevant to an area of inquiry.