D : This means the process is in uninterruptible sleep mode. Usually Input and output are in this mode.
R : Currently Running Process or is in the running queue.
S : Is in sleep state waiting for an event to complete.
T : Means the process is stopped by a signal.
X : X means a dead process.
Z : Zombie or dysfunctional process which has terminated.
< : High priority process
N : Low priority process
L : This represents a process which has pages locked into the memory for real time processing or input output.
s : Means that this process is leading the session.
l : Multithreaded process.
+ : Running in the foreground.
Sending Signal to Processes :
Send Continue Signal to a Process :
kill -19 pid