All the files and directories in Linux  have below 3 permissions, represented by a three digit octal value .- Read - It provides the ability to read the contents of a file (represented by 'r' in the first position "r--") Write - It Provides the ability to edit or delete the content of a file (represented by 'r' in the second position "-w-") Execute - It Provides the ability to execute the file (represented by 'x' in the third position "--x") The octal value is calculated as the sum of the permissions: “read” is 4 “write” is 2 “execute” is 1