The primary difference is that a turntable is indeed a part of a record player. A record player setup has a speaker and an amplifier built-in so that it can play records by itself. So all a record player needs is a power cord, and it will take care of everything else. Turntables do not have a speaker or amplifier, and those things need to be bought separately. So a turntable is that part of a record player apparatus that holds and spins the record. An advantage of a turntable is that it is highly customizable as you can connect it to the bookshelf speakers of your choice, usually through an RCA cable. At the same time, record players have their speakers, preamp, and amplifier attached. Hence, there is not much opportunity for customization. Another advantage that the turntable has over a record player is that it is much more portable and can easily be picked up, packed and moved from one place to the other. Record players are usually reserved for one dedicated area of the house and are not moved from there. So both record players and turntables have their advantages and drawbacks.