alt Hacker NewsTechnically the difference is clear. Return is for character based protocols, teletypes, ttys, VT100, ssh and the like.
Enter is for IBM 3278 style where a "screenful" or form of inputs is buffered by the terminal and sent as a whole when the user presses enter or send. Fewer interrupts and context switches at the mainframe. Required even its own ssh client. Return key exists, too, and can be part of the buffered data record.
In practice the enter term leaked into the character-based world.
And of course ASCII separates them, with LF (linefeed, sometimes called newline) and CR (carriage return, or just return) being two separate characters. Windows (and probably some other) text file conventions used CR+LF to end a line, while unix conventions used just LF (hence the alternate name of "newline").