Represents the definition of a single approval process. Use this object to read the description of an approval process. The definition is read-only. We can not modify the record created in ProcessDefinition Object. But we can describe, query, search and retrieve the approval processes information.
~ Query ~
SELECT CreatedById,CreatedDate,Description,DeveloperName,LastModifiedById, LastModifiedDate,LockType,Name,State,SystemModstamp,TableEnumOrId,Type,Id FROM ProcessDefinition
The records are created when we create a new approval process using Salesforce user interface of Approval Process.