Help me in awk commands

can you please let me know what does the below awk command does.

 
 
awk 'NR>2{printf "%-30s  %-15s\n", $1, !($4)?$2:$4;}' result.txt

It skips 2 lines of the input file "result.txt" and then prints the first field and the fourth, if not empty, or the second, if fourth ist empty/non existant.