ps

Process-Monitoring

PID – the process id
TTY – terminal associated with the process
TIME – elapsed CPU utilization time for the process
CMD – the executable command

# With -f option, it'll add the following columns:
UID – the user id of the process owner
PPID – the parent process id (in this particular snippet, rcu_gp was spawned by kthread)
C – the CPU utilization in percentage
STIME – the start time of the process

Furthermore, when ps can identify the process arguments, it will also print them in the CMD column.

# Print the processes of the current user and terminal 
ps
# Print all the processes within the system
ps -e
# Search for a particular process name
ps -C myProcess
# Search for a particular process ID
ps -p 1,765
# Search for a particular user
ps -u root
# Listing Threads
ps -C myProcess -L
# Listing Child Processes (can't filter by process)
ps -e -H
# List real user and effective user
ps -C passwd -o pid,tty,ruser,user,cmd