Forum Thread: Some questions about commands:)

In command:nice -n -20 airbase-ng -a 00:09:5B:6F:64:1E --essid "Elroy" -c 11 mon0,what's "-a 00:09:5B:6F:64:1E --essid "Elroy" -c 11 mon0" means? And i wonder how the nice value hint to the kernel and why we don't use nice value when we use renice command...