Considering JSON (JavaScript Object Notation), is JSON itself a language, or is it only defined in context of another language? By language, I
I would classify it as a format of structured data, not a language. This Wikipedia article about Turing completeness does a pretty good job summing it up:
The notion of Turing-completeness does not apply to languages such as XML, HTML, JSON, YAML and S-expressions, because they are typically used to represent structured data, not describe computation. These are sometimes referred to as markup languages, or more properly as "container languages" or "data description languages".