In your terminal (must be bash) enter the following command:
$ info command
This will print out a detailed text document for the particular command, that goes in-depth on how to use a particular tool. And is extremely helpful in learning:
How to use a program/tool (Here’s looking at you
Finding parallels between how the program works and how to use your particular language to implement them.
You may be able to search for these on the internet, but I have not tried myself so cannot guarantee anything. But it’s the internet, so…
EDIT: If you don’t have a version of Linux or Windows Subsystem for Linux. You can find all the manuals for any GNU program here: https://www.gnu.org/software/