How can different domain sellers sell the same domain?

Question

When I go to two different sites that both offer domains I can buy the same domain at both websites. Doesn't that mean they both own the same domain?

Answer 1

The domain registrars do not own all of the domain names they are selling. They are accredited by either global our country domain registry to provide domain names to particulars.

Basically this means that until a domain name is registered for the first time it does not belong to anybody. Once it registration expires it returns to the pool as well.

For further reading on Domain name registrars