Testing Article Sections: How Queries Work – GROQ
The idea behind our query language GROQ (Graph-Relational Object Queries) is to be able to describe exactly what information your application needs, potentially joining together information from several sets of documents, then stitching together a very specific response with only the exact fields you need.
If you need help setting up a client to perform these queries in your front end, you should check out the documentation for the client for JavaScript or PHP. You can also check out the GROQ Arcade if you want to query any JSON source and get familiar with the language.