The "comm" Utility
The "comm" utility is used to either display or censor equivalent lines that appear in two files.
The "comm" utility uses columns to differentiate which file a unique or shared terms can be found. The first column is used to list items unique to the first file. The second column is used to display terms unique to the second file. And the third column is used to list items common to both. The "comm" utility has several interesting options to modify the column displays
Consider these examples