Linux Filter commands accept input data from stdin (standard input) and produce output on stdout (standard output). It transforms plain-text data into a meaningful way and can be used with pipes to perform higher operations.
| 1 | grep | global regular expression print → filters the content of a file which makes our search easy.
E.g : cat /etc/passwd | grep root or ls -ltr | grep videos |
| 2 | sort | sort <fileName> , eg : sort /etc/passwd |