A starship is a type of vehicle that is capable of supporting a living crew traveling over interstellar distances. Starships are capable of faster-than-light speeds using warp drive or other propulsion methods. A starship's specification is largely determined by its class.
Vessels which are not interstellar capable (i.e. interplanetary) are generally referred to as space ships. The terms "spacecraft", "starcraft", or even "vehicle" are used interchangeably.
The term generally can be applied to any interstellar spacecraft, but is most frequently applied to the ships operated by the Federation Starfleet.