Here is the video version, if you prefer it:
The man command is used to display usage information regarding a certain command. (“man(1) – Linux man page,” n.d.) For example, if I wanted to know how to use the ls command, I would write:
mislav@mislavovo-racunalo:~$ man ls
The man page for the ls command would open and then you can see the usage information regarding the ls command. You could scroll through the man page by using Space on your keyboard (to move forward one page) and Q to exit man page viewing. To go backward for 1 page, press B. The answer in the reference here says to press CTRL + B (or ^B in Linuxspeak), but you can just press B. (as is said in the comment in the reference; it is always good to read stackexchange comments!) (“How to read backward from the end of file in less or more?,” n.d.)
That way, if you forget to use a command, you can always find out its usage information. Although I have found myself very rarely using the man command (because I know the syntax of the commands I often use by heart, or use Google to find their usage in my particular situation), it can come in handy to know that you can always have the man there waiting for you if all else fails.
Hope this helped!
Additional information tidbit:
You can even access the man pages of man by writing man man. Manception!
References:
How to read backward from the end of file in less or more? (n.d.). Retrieved January 6, 2020, from https://serverfault.com/questions/151635/how-to-read-backward-from-the-end-of-file-in-less-or-more
man(1) – Linux man page. (n.d.). Retrieved January 6, 2020, from https://linux.die.net/man/1/man