[nocman]

As the previous replies stated, the "1" is the section of the manual the page you are requesting occurs in.

If you have trouble remembering what the sections are, I recommend running "man man" in the terminal. The section numbers are explained near the beginning.

[jjgreen]

Irix (IIRC) used to respond to the argumentless command "man" with the supremely snotty "appropo what", which made me laugh out loud the first time I saw it