File descriptors

In Unix and Linux since Linux was modelled on Unix lots of things look like file descriptions. Sockets, things that you can access in the core operating system etc. can be treated like files.

For instance the ::write command in Unix operating systems can be used to write data to a socket or to a file. Unix has a lot of symmetry in this way. For this reason I sincerely believe that Linux and Unix based systems have a better design than Windows which has a lot of special cases for different operating system functions.