The port side is the left side looking forwards towards the bows, and the starboard is the right side. Port was originally called larboard, but the word was altered to avoid confusion in sound. Starboard means steer-board, or steering side, for the great oar used for steering ancient ships was on the right side of the stern. At night, a ship shows a red light on her starboard side. Both of these lights can be seen at the same time only when the ship is coming straight at the observer.
Port and starboard (Wikipedia)