the command echo is used to display a line of text.

the command grep allows the user to find special patterns within files and displays the lines to the user.

the command head prints the first ten lines in a file.

the | Operator redirects the output of one command and pipe it as input to another.

(ls/usr/bin |sort)

|

the command tail prints the last ten lines in a file.

the < operator redirects input.

the > operator redirects output to a file.