For a desired combination of access rights, the octal number is calculated by adding:
The default access rights for directories are 755, i.e. the owner can read and write and browse the directory and all others can only read and browse it. Since usually applications on Unix-like systems are installed by the administrator (usually called root), this means that except for root, users will only be able to browse directories and read from them but they will not be able to create files in them. If you have directories that your users should be able to create files in, you have to set a different access mode for them. For example, 777 would allow all users to create, read, write and delete files in the directory. You can reset the default mode with the [Reset to default] button.