| Status | Description |
| dormant | SQL Server is resetting the session. |
| running | The session is running one or more batches. When Multiple Active Result Sets (MARS) is enabled, a session can run multiple batches. |
| background | The session is running a background task, such as deadlock detection |
| rollback | The session has a transaction rollback in process |
| pending | The session is waiting for a worker thread to become available |
| runnable | The session’s task is in the runnable queue of a scheduler while waiting to get a time quantum. |
| spinloop | The session’s task is waiting for a spinlock to become free |
| suspended | The session is waiting for an event, such as I/O, to complete |
Reference taken from microsoft books online
aiDeeva.com 