Some Nintex workflow actions create tasks on the SharePoint site, for example both the Assign Flexi task and Request Approval actions create tasks. These tasks are by default created on the sites ‘Workflow Tasks’ list. If you would like all the tasks for a specific workflow to have it’s own tasks list, you can setup the Nintex Workflow to create it’s own Task list.
Even Lazy Approval Flexi Tasks still create actual tasks on the site, the task list can be a great resource to review active tasks (i.e. tasks that have not been completed) or to review who approved which task and when.