The Linux system contains thousand of files located within many directories. All directories are organized in a tree-structure like manner. For novice users the linux directory structure may seem unlogical and strange and they may have no idea where all the programs, icons, config files, and others are. However, all files are grouped according to purpose. Parts of a Unix directory tree are listed below. All directories are grouped under the root entry “/”.
If you’re a new linux user, I found a nice picture explaining the linux file structure which might be useful - check it out at secguru
