This link should take you to the TaskStatusTypes javadocs.
http://livedocs.adobe.com/livecycle/es/sdkHelp/programmer/javadoc/com/adobe/idp/taskmanager/dsc/clie...
There are 4 status' for active tasks, CREATED (1) and CREATED_SAVED (2) for active tasks that start processes, where the process instance isn't created until this task is completed, and ASSIGNED (3) and ASSIGNED_SAVED (4) for active tasks associated with a process instance. The _SAVED status means that an incremental save of the data was done such as Save To Drafts from Workspace.
Non-active tasks are COMPLETED (100), DEADLINED (101) and TERMINATED (102), note that all are >= to the COMPLETED status, so conversely, any status < COMPLETED is active.