Pay attention damit!
Pressing a key on the piano’s keyboard causes a felt-covered hammer to strike steel strings. The hammers rebound, allowing the strings to continue vibrating at their resonant frequency. These vibrations are transmitted through a bridge to a sounding board that couples the acoustic energy to the air so that it can be heard as sound. When the key is released, a damper stops the string’s vibration. Pianos are string instruments. According to the Hornbostel-Sachs method of music classification, they are grouped with chordophones.
The word piano is a shortened form of the word pianoforte, which is derived from the original Italian name for the instrument, clavicembalo [or gravicembalo] col piano e forte or literally harpsichord capable of playing at the normal level.