A harp is a large, stringed musical instrument with a beautiful sound. If you want to play an instrument that's portable, you should choose a ukulele instead of a harp.
Many orchestras include a classical harp, which is such a big instrument that players usually need assistance to move them. Harps are played from a sitting position, resting on the player's shoulder as she plucks the strings with both hands. A folk harp is often smaller, sometimes sitting on a player's lap. When harp is used as a verb, it means to talk constantly and dully about one topic: "The harpist did nothing but harp on about the weather."