First slot: Is it a file or directory? Next set of triple slots is for the User, then the next three is for the Group and finally the last 3 spots is for Everyone. File permissions can also be represented using octal notation. r is 4(2^2), w is 2(2^1), and x is 1(2^0). So if it's readable, writeable and executable, it means it's a 7. If a file or directory is readable and executable but not writeable then that's a 5. You can convert between symbolic and octal representation using this tool.