Ok, I did a search in here on this and came up with nothing so I thought I would ask you guys.

What is the short and sweet explanation of ETOPS? I know it is cert. required of aircraft flying over the open ocean and has something to do with the equipment installed in the flight deck. What specifically does it mean when, say, a 752 or 753 is ETOPS certified? What is the difference from a standard 757? Also, which aircraft come ETOPS cert. on the standard model (I assume all the international, long range aircraft like the 747, 777, A330 and A340.

Thanks for any info.