e.g.
$ wc myfile.txt
-> 5 13 56 myfile.txt
5; total row number
13; total word number
56; total character number
$ ls | wc -l
-> Total number of files in current directory
$ wc myfile.txt
-> 5 13 56 myfile.txt
5; total row number
13; total word number
56; total character number
$ ls | wc -l
-> Total number of files in current directory