The guitar usually has six strings and can be played by plucking or strumming strings while pressing down on strings at the top of the guitar to change notes. Guitars used to be made out of wood and natural fibers, but strings began to be made out of steel in the late 1800s, and the modern nylon strings were introduced in the 1940s. The guitar has many types, including the classical guitar and the electric guitar. Guitars are used in a large spectrum of music genres, including folk, jazz, and pop, but is not commonly found in classical music. Read more here: https://en.wikipedia.org/wiki/Guitar