To put it simply, this is a big version of xylophone. However, this is a different musical instrument than the xylophone. While both can be called the "keyboard of the tree", the marimba has a much lower range of sound compared to the xylophone. I usually use a marimba that has five octaves and is about 3 meters in length. By the way, the keys are lined up the same as the piano. Compared to the xylophone the marimba is deeper and softer with a profound sound that sounds very warm. I guess if you compared them to different instruments the xylophone would be the flute and piccolo while the marimba would be the violin and contrabass. The origins of the xylophone and marimba are the same but because differences with the place of origin, the time period, and the route of development/conveyance both became different instruments.

For more details click here →

Basically, this is a big version of the glockenspiel. However, the vibraphone is a completely different instrument. While both are "keyboards of metal" the vibraphone has a much deeper range than the glockenspiel, usually using 3 octaves (F2-F5). Also, while the keys are lined up the same as the marimba or piano there is no difference of height of sound between the accidental notes (the black keys of a piano) and the natural notes (the white keys). The biggest differences from the glockenspiel is that the vibraphone, like the piano, has pedals and there is an electric motor on the upper part of the resonance tube that makes the sound change into "vibrato" like a Hammond organ. If you were to compare the differences between the vibraphone and the glockenspiel to other instruments you could say they are comparable to the difference between a soprano and tenor saxophone. The origin of the vibraphone and glockenspiel  are the same but because differences with the place of origin, the time period, and the route of development/conveyance both became different instruments.