In general terms, a disciple is someone who follows another. John the Baptist had disciples (John 1:35), the Jewish religious leaders had disciples (Luke 5:33), and Jesus had disciples (Matthew 10:1). Also, the Pharisees affirmed that they were Moses’ disciples, albeit centuries after Moses’ death (John 9:28).
Sometimes Disciple, as a proper noun, refers to one of Jesus’ original twelve followers, whereas other times it refers to any follower of Jesus (John 8:31).
Often the terms disciple and apostle are used interchangeably, although some would say that a Disciple is one of the original twelve followers, whereas an Apostle is a more generic term that applies to all followers of Jesus.