All percussion instruments are played by either hitting them with something or crashing them together. Since the Vibraphone is hit with a mallet to produce sound, then it would be considered a percussion instrument.
Some instruments similar to the vibraphone are the xylophone and the marimba (wooden), the glockenspiel/Bells (metal) and the piano. All are keyboard instruments, and with the exception of the piano,...
There are many instruments which can be played in a percussive manner but are not classified as a percussion instrument. Just because an instrument is not classified as a percussion instrument does...
Percuss is a medical term, to strike. When the doctor percusses your chest, she is striking it. So a percussion instrument is struck, mainly. There are others that you can shake, rattle or stroke,...