Linux keeps files in a single hierarchical directory structure, that (behind the scenes) is made up of a combination of hard drives, CD-ROMs, floppy disks, ZIP drives, etc.
The typical Linux filesystem looks like this:
/
|- bin Essential binaries
|- boot Boot information
|- dev Devices
|- etc Configuration files
|- home Users' home directories
| |- user1
| |- user2
| |- user3
|
|- lib System libraries
|- lost+found Files recovered after filesystem checks
|- mnt Mount point for removable disks
| |- cdrom (An alternative is /cdrom and /floppy)
| |- floppy
| |- zip
|
|- proc A special directory with file-based system information
|- root Home directory for the root user
|- sbin Essential system binaries
|- tmp Temporary work space
|- usr
| |- X11R6 X-Windows files
| | |- bin
| | |- include
| | |- lib
| | |- man
| | |- share
| |
| |- bin Binaries
| |- dict Dictionary
| |- doc Documentation
| | |- HOWTO Linux HOWTOs - guides to various aspects of Linux
| |
| |- etc Additional configuration files
| |- include Include files for the C preprocessor
| |- info GNU info files
| |- lib Additional libraries
| |- local Files generally not supplied by the distribution
| | |- bin
| | |- doc
| | |- etc
| | |- include
| | |- lib
| | |- man
| | |- sbin
| | |- share
| |
| |- man Man (or manual) pages
| |- share Shared files
| |- sbin Additional system binaries
| |- src Source code directories (eg. /usr/src/linux/)
|
|- var
|- lock Lock files
|- log Log files
|- spool Spool files
|- mail Users' mailbox files