All files on UNIX (including Linux and other UNIX variants) machines have access permissions. In this way the operating system knows how to deal with requests to access the files. There are three types of access:
- Read - Denoted as r, files with read access can be displayed to the user
- Write - Denoted as w, files with write access can be modified by the user
- Execute - Denoted as x, files with execute access can be executed as programs bythe user
Access types are set for three types of user group:
- User - The owner of the file
- Group - Other files which are in the same folder or group
- World - Everyone else
