AutoAPI is a car data protocol developed by High Mobility.
It defines a common schema for different car brands, so a user of the protocol can access data from different manufacturers unified into a single schema.
More information regarding AutoAPI can be found here.
The JSON Schema is a version of the same AutoAPI protocol, but in a different format - JSON. More information about the JSON Schema can be found here.
The schema presented here, is available to use to verify and understand the output from High Mobility's AutoAPI in JSON format.
The schema-files are divided into separate files, categorized as capabilities and misc.
Different capabilities are described in more detail here (starting after the Getting started section).
The misc JSON Schema files are commonly used types (in capability-files) and unit types.