In this short, we're viewing the system manual (i.e., "the man pages") with the man command using the -S option.

The SEE ALSO section

Take special notice of the SEE ALSO section after viewing the initial man intro command and how it shows further information in the following sections:

man(1) intro(2) intro(4) intro(8)

To further inspect those new sections of the manual, use the -S option to specify the section of interested. In this case, we'll further inspect section 2 of the intro command. Alternatively, you can leave off the -S option and lookup the section with the following:

man 2 intro

Using the cat command

The man command's output is piped to the cat command in these examples only for the purposes of paging the output via the less command (the default behavior for man).

Using the clear command

The clear command is used here to make the example easier to read, but you can use it any time you need a clean slate in your terminal.