What does the option '-f' specify in the 'cut' command?

The -f option in the cut command specifies the fields to be extracted from each line of input. It is used in conjunction with the -d option, which defines the delimiter that separates the fields. For example:

cut -d',' -f1,3 filename.txt

This command would extract the first and third fields from each line of filename.txt, using a comma as the delimiter.