Windows won the OS wars and that’s why I don’t know these subtle differences.
All keyboards have a dedicated Return key — it’s the big key you’re thinking of above the right Shift key. On a Mac, the key code when you press Return is 36, and the glyph for the key is ↵.
A dedicated Enter key is generally only present on extended keyboards with a numeric keypad — it’s the key in the lower-right corner and is generally the only oversized key on the keyboard that is larger vertically, not horizontally. Its Mac key code is 76 and its glyph is ⌅. Just look at such a keyboard: the Return key says “Return”, and the Enter key says “Enter”.
Return and Enter Are Two Different Keys