The pipes that in the shell are representend with the symbol | , they are used to join two commands on the terminal, taking the output of the first command and using it as input of the second.
It is usually common to see the command grep and ps together, an example below.
ps aux | grep user
Lists all processes with your username
cat example1.txt | nl 1 Car 2 Computer 3 Robot 4 Smartphone 5 Videogame
In this example you send this output to another process, in this case, the nl
You can use the commands that you learned and put them together, always respecting the logic of the command.