/bin: Unix binaries. This is where the common UNIX commands (for example, ls, rm, mv, df) are./sbin: System binaries. These are binaries used for system administration, such as file-system management, network configuration, and so on./usr: The User directory. This is not meant for users, but is more like Windows’ program files in that third-party software can install here./usr: Contains in it bin, sbin, and lib. /usr/lib is used for shared objects (think, Windows DLLs and \windows\system32). This directory also contains the include/ subdirectory, where all the standard C headers are./etc: Et Cetera. A directory containing most of the system configuration files; for example, the password file (/etc/passwd). In OS X, this is a symbolic link to /private/etc./dev: BSD device files. These are special files that represent hardware devices on the system (character and block devices)./tmp: Temporary directory. The only directory in the system that is world-writable (permissions: rwxrwxrwx). In OS X, this is a symbolic link to /private/tmp./var: Various. A directory for log files, mail store, print spool, and other data. In OS X, this is a symbolic link to /private/var.
