A user can activate a workflow on documents or workflows from the Workflows panel in the File/Folder view:
A workflow can also be activated by an event. For example, you can automatically activate a workflow when a tag is created on a specific folder/file:
A workflow can also be activated by calling it from another workflow:
In this case, the 'Submit' task of 'A Development Workflow' calls 'A Testing Workflow'.
Once a workflow is activated, the users or groups assigned to the workflow can complete the workflow tasks. If a workflow task is assigned to a group, any user who belongs to the group can complete the task. In this case, the task will be recorded as completed by the group. The task can also be claimed and completed by a user in the group. In this case, the task will be recorded as completed by the user.