This error will come when you try to logout or exit from a terminal and there are some tasks which are running in background.
surendra@linuxnix.com:~$ ping linuxnix.com
PING linuxnix.com (216.239.38.21) 56(84) bytes of data.
64 bytes from any-in-2615.1e100.net (216.239.38.21): icmp_req=1 ttl=50 time=61.3 ms
64 bytes from any-in-2615.1e100.net (216.239.38.21): icmp_req=2 ttl=50 time=63.2 ms
^Z
[1]+ Stopped ping linuxnix.com
surendra@linuxnix.com:~$ exit
There are stopped jobs.
surendra@linuxnix.com:~$
If you observe I started a ping program and sent that process to background. And when I try to logout from that terminal I got an error stating that there are still some programs running. To stop this error we have to see if you really like to kill the jobs.
How to kill those jobs?
Execute/press below commands/shortcuts
fg
ctrl+c
How to retain job running though you try to logout?
Just press below commands/shortcuts
ctrl+z
bg
disown
This will allow us to run the process in background though you try to logout.