Guitar is the rhythm of the music, it serves as the accent and flare to every song. It states the mood and beat and controls the tempo. It can be called the backbone of every song for it is the basis of how a certain song's sound would end up.
There are different types and every one is suited for a certain sound. The electric guitar uses a pick up and an amplifier speaker to produce sound.
Actually, I can't tell if this is a spambot or just someone who fails to make me see the purpose of his thread. I'm betting on the former though.