Buzz,
there's no such thing as a 'dumb question'!
I wouldn't disagree with any of the excellent explanation CanusLatransSnpr posted, but would add a couple of things.
6X47 (or 6X47mm) is strictly the necked-up .222 Rem Magnum, but a lot of people who refer to '6X47' now really mean the other one, as it's modern and topical and all that. The 'other one' is the necked down 6.5X47mm Lapua which is sometimes called 6-6.5X47mm, but a lot of people find that a bit of a mouthful, so they often abrreviate it to 6X47L, the 'L' showing it's based on the Lapua not the Remington case.
Lots of people thought the 6X47L / 6-6.5X47 was going to put the 6BR out of business as the 600yd BR topdog, but it doesn't seem to be working out that way. Although it has its fans and it does give more velocity than the 6BR, 6BRX, 6 Dasher 'family', there seems to be a growing concensus that it is inferior accuracy-wise and that's what counts most for a lot of BR users. Morale of the story, apart from not confusing people with old names on new cartridges, seems to be not to rush to take up the latest new thing, but wait and see if it's better as well as newer!
Hope this helps,
Laurie,
York, England
PS re the deer - I'm not a deerstalker (deerhunter on your side of the Atlantic) myself but know many who are, and read all I can on sporting use of any and every cartridge. The 'old' 6X47 (.222 with a 6mm bullet) never caught on for deer on either side of the Atlantic, but a few afficionados on youre side rate it highly for pronghorn antelope and the smaller regional Whitetail varieties. The modern 6X47L is a more powerful cartridge but still less so than your ordinary .243 Winchester, but gives rather less recoil. Its parent cartridge, the 6.5X47 Lapua is a fine multi-purpose smaller deer and long-range varmint cartridge, and is designed to feed from magazines in short-action repeaters. Performance wise it's not far apart from .260 Rem and the new 6.5 Hornady Creedmoor, but is very much a handloading proposition. Over here in the UK, the brass is very expensive, and I guess it will be in the US too, but it's very well made and strong, so will last a long time. If you're having a custom rifle built, it could be a good choice, but if you want off the shelf, the choice is really between .243 Win and .260 Rem.