Civil ceremony? Renewal of vows? Plain ol' marriage??

I have a 2-part question -  pardon if it's completely silly. What exactly is a civil ceremony? What's the difference between that and a regular ol' ceremony? All the venue sites I've looked at only give information about civil ceremonies.
My second question is specific to my situation. I'll be getting married in the US in 3 weeks (yay!) and then moving to the UK. We're doing things a bit un-traditionally (as I'm sure many people do, living in different countries and all!), and we'll be having 2 weddings. The wedding in 3 weeks will just be me, my hubby-to-be, and a Pastor (happens to be my brother). We'll be signing the license and be legally married then. Next year, we're having the whole sha-bang wedding with tons of guests and a reception and everything. I'm wondering if anyone knows how a renewal of vows ceremony works in the UK. Can we have it wherever we want, or does it need to be an "approved" venue? I'd like my brother (an American) to conduct our vow renewal ceremony - is that "legal", or does it even have to be "legal"?? Ahhhh, so many questions...thanks for your help!

Well, the differences are that a civil ceremony is performed by a registrar, and it is without any religeous tone, wording, prayer, etc by law. It's a legal ceremony as you would have if you went to the Justice of the Peace in the US. The other option is a church ceremony, where the ceremony is performed either in a church, or by a church official/priest/vicar, etc.

You could always have a 'blessing' ceremony later, after you are already married, but if you wanted to do it in a church over here, you would most likely have to have the vicar perform it, rather than your brother. You could always do a 'blessing' at another venue, but it's mostly ceremonial, rather than an official thing, so I don't think it would be a problem.

Congrats on your upcoming marriage

If you're having your legal wedding in the US and renewing your vows over here, it doesn't matter who officiates (from a legal standpoint) as you will already be married. A renewal ceremony has no legal standing. So you can have who you like and do it where you like as well, without worrying about approved venues. 

I agree with the PP, can't answer conclusively for the UK, but in the US for sure a renewal ceremony has no legal standing, and people have been known to do them underwater in scuba gear, hanging upside down from trapeze with a clown "officiating"...you can really do whatever you like as it's only the first ceremony (the one for which you fill out all the legal paperwork) that has any legal significance whatsoever.  From anecdotal evidence I've heard, the UK is just the same...however many times you want to repeat your vows, and however extravagant (or weird) a party you want to throw to accompany said vows, is completely up to you.

The only legal consideration (in the US) is that the person officiating the marriage the first time be someone legally entitled to perform marriages and sign the marriage certificate, and that you have said certificate and associated licensing taken care of before the actual ceremony.