How to fix error when starting apache2?

Question

Apache HTTP Server

Guys, who can help? Faced a problem when starting apache2 on ubuntu20.04 gives the following error:

Mar 31 16:17:29 server1 systemd[1]: Starting The Apache HTTP Server...
Mar 31 16:17:29 server1 apachectl[160816]: (98 )Address already in use: AH00072: make_sock: could not bind to address [::]:80
Mar 31 16:17:29 server1. apachectl[160816]: (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
Mar 31 16:17:29 server1 apachectl[160816]: no listening sockets available, shutting down
Mar 31 16 :17:29 server1 apachectl[160816]: AH00015: Unable to open logs
Mar 31 16:17:29 server1 apachectl[160806]: Action 'start' failed.
Mar 31 16:17:29 server1 apachectl[160806]: The Apache error log may have more information.
Mar 31 16:17:29 server1 systemd[1]: apache2.service: Control process exited, code=exited, status=1/FAILURE
Mar 31 16:17:29 server1 systemd[1]: apache2.service: Failed with result 'exit-code'.
Mar 31 16:17:29 server1 systemd[1]: Failed to start The Apache HTTP Server.

What to do?

Answer 1

See which program has occupied port 80 and shoot it.