more(1) is what we call a pager utility. Oftentimes the output of a particular command is too big to fit on one screen. The individual commands do not know how to fit their output to separate screens. They leave this job to the pager utility.
The more command breaks the output into individual screens and waits for you to press the space bar before continuing on to the next screen. Pressing the enter key will advance the output one line. Here is a good example:
$ cd /usr/bin $ ls -l |
That should scroll for a while. To break up the output screen by screen, just pipe it through more:
$ ls -l | more |
That is the pipe character (shift backslash). The pipe is short for saying “take the output of ls and feed it into more”. You can pipe just about anything through the more command, not just ls. Piping is also covered in the section called Input/Output Redirection and Piping in Chapter 8.