How do online car dealers work?

[BewareTheBeardedDragon]

Looking for a used car and can only so far find what I want online. I've only ever bought via a bricks and mortar dealership before and I'm a bit worried about buying online.

Can anyone explain how they work? Are they just middlemen or do they actually buy and sell the cars? I don't want to buy privately because I don't know enough about cars to be sure I'm not buying a doozy.

For instance I e found the car I want - one on auto trader, who I think are a middleman? And one on Heycar who maybe aren't?

Any advice warmly received.

Auto trader is like Rightmove car dealers or private sellers put their adverts on for customers to search - if you click on the advert it should say who is selling it private or trade (car dealer) and where they are based

Some online sites have bricks and mortar behind them and you have all the protection, but others are private individuals. I'd not buy from an individual (as the car is yours when you agree to hand over the money). With a company, you get a 14 day cooling off period (extended if there are issues in that time) which is pretty essential when you are buying unseen.

Thanks, that's helpful.