When you use *nux man command, you’ll see number after commands or system calls. e.g. LS(1), FORK(2).
What’s this number? It’s called section number.
The next question is, what does the section number actually mean?
Section numbers
| section number | description |
|---|---|
| 1 | Executable programs or shell commands. |
| 2 | System calls. This functions are provided by the kernel. |
| 3 | Library calls. This functions are used as program libraries. |
| 4 | Special files. This is usually found in /dev. |
| 5 | File formats and conventions, e.g. /etc/passwd. |
| 6 | Games. |
| 7 | Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) |
| 8 | System administration commands. This is usually only for root. |
| 9 | Kernel routines [Non standard] |
- This list is based on Linux
mancommand (You can see it by runnningman man).