How do you know if it is a compound sentence?

A typical compound sentence has two or more clauses linked by coordination with each one having its own subject and predicate. Usually, there is a coordinating conjunction like and, but or or joining the clauses:

Tom likes beer and Ed likes whisky but Fred prefers brandy.

I like this hat but I don't like that one.

Do you like this car the best, or do you prefer the other one.

PaulM