Understanding the difference between GROQ and GraphQL query languages for JSON.

ah, now I really don’t understand the advantage of GROQ over GRAPHQL

You can think of GraphQL as REST and GROQ as SQL. The former is more of a API pattern, the latter is a query language for JSON. They do some of the same things, but the latter is more versatile in terms of what you can do. We use GROQ to power the GraphQL API for example.

There’s so many different query languages already.

I understand there is a spec for GROQ, but nobody else is using it.

afaik

Yup, there are, but this one is for JSON documents 🙂
And it’s fairly new, but are being adopted outside of Sanity as well.

But no pressure – you can use GraphQL if you prefer that, many do!