1. Car boot sale This is held out of doors, usually in large car park or open space, often on a Sunday morning. People park and open up their boots (trunk for AmE readers). They normally put up a folding table behind their cars and sell bit and pieces of things from this table. Car boot sales aren't usually charity events. They're a means of getting rid of stuff and making some spare cash. Some people might also collect items and attend car boot sales regularly as a means of making a small amount of extra income, but professional traders are usually not allowed to take part. Participants usually pay a fee to the organisers for their 'pitch' (space), but take home all the money they make. Bring-and-buy sale This is probably indoors and organised by a school or church, for example. Depending on how it's organised, you might donate objects to sell on the day, or you might take them to the venue at an earlier point. Note that the objects you bring are donations - you bring them to be sold to help the organisation raise money for itself or for a charity. All the money raised goes to this cause. Jumble sale This is similar to a bring-and-buy sale. Like a bring-and-buy sale, it conjures up an image of long tables in a church hall, piled high with clothes, toys, books and ornaments. The people manning these tables and taking the money are volunteers who've offered to give up some time to help raise funds for a good cause. There'll also probably be refreshments (teas, coffees, soft drinks, cakes and biscuits), also to raise money for the charity or good cause. The only difference between these two events is that you wouldn't bring anything to a jumble sale - the goods have been collected beforehand.

At a car boot sale individual members of the public bring their items for sale to the location by car - often it might be a field or a car park, maybe at a school or community centre. Each seller pays an entry fee and this is the money that might be used to raise money for a charity. Usually the sellers set up a table by their car where they display their items and sell them to the buyers for cash. People who sell at a car boot sale might be trying to raise some extra cash or just clearing out their home. A bring -and- buy sale is something I associate with community organisations. For example, if you belong to a community group one meeting each year might be devoted to a sale. Each person brings just one or two items to sell and the money raised is donated to charity. Things I have seen at bring and buy sales include - baked goods, unwanted gifts, ornaments, or luxury food items (wine, cakes , chocolates etc), books or nice stationery. A jumble sale is usually an urban event. I attended many when I was a student in London. Old clothes and household goods are set out (piled up) on tables - usually in a church hall or community centre - and people pay very small amounts of money for each item they want. The purpose is usually to raise money for a charity as well as to provide a source of cheap items for people who live in a neighbourhood.