What does the number in parentheses shown after Unix command names in manpages mean?

Question

For example: man(1), find(3), updatedb(2)?

What do the numbers in parentheses (Brit. "brackets") mean?

Answer 1

It's the section that the man page for the command is assigned to.

These are split as

1. General commands
2. System calls
3. C library functions
4. Special files (usually devices, those found in /dev) and drivers
5. File formats and conventions
6. Games and screensavers
7. Miscellanea
8. System administration commands and daemons

Original descriptions of each section can be seen in the Unix Programmer's Manual (page ii).