D = uninterruptible sleep (waiting for io) R= running S = interruptible sleep T= stopped by job control signal t= stopped by debugger with tracing x = dead z= zombie (dead) waiting for its return value to be recovered by parent process Source: ps man page

Halt, running, terminated

NEW- The process is being created. READY- The process is waiting to be assigned to a processor. RUNNING- Instructions are being executed. WAITING- The process is waiting for some event to occur(such as an I/O completion or reception of a signal). TERMINATED- The process has finished execution.