Difference between executionId and processInstanceId?

[pero]

I was wandering what's the difference between executionId and processInstanceId task parameters?

I want to search all task's for some process definition that are active(not completed).

[jbarrez]

A process instance is also an execution. The process instance id = the root execution id of the tree of all executions.
Ie, when the process splits into two parallel paths, there will be two executions under the root (ie process instance)

[pero]

Got it. Thanks for clarifying that one.