A task instance can have its own set of variables and a task instance can also 'see' the process variables. Task instances are usually created in an execution path (=token). This creates a parent-child relation between the token and the task instance similar to the parent-child relation between the tokens themselves. The normal scoping rules apply between the variables of a task instance and the process variables of the related token. More info about scoping can be found in the section called “Variables scopes”.

This means that a task instance can 'see' its own variables plus all the variables of its related token.

The controller can be used to create populate and submit variables between the task instance scope and the process scoped variables.