How do you display the manual for a command?

Use the man command followed by the command name, e.g., man ls. Man pages are divided into numbered sections: section 1 is user commands, section 2 is system calls, section 5 is file formats, section 8 is admin commands. Specify a section with man 5 passwd. Within the man pager, use arrow keys or j/k to scroll, / to search, and q to quit. man -k keyword (or apropos keyword) searches all man page descriptions. --help or -h flags on most commands also give quick usage summaries.