What is Query?
Query meaning A type of question accepted by a database about the data it holds. A complex query may ask the database to select records according to some criteria, aggregate certain quantities across those records, etc. Many databases accept queries in the specialised language SQL or dialects of it. A web API allows an app to send queries to a database over the web. Compared with downloading and processing the data, this reduces both the computation load on the app and the bandwidth needed.
reference: Open Data Handbook – Glossary