What is the purpose of the large flat piece of wood within a piano, and how does it serve the same function as a soundboard in other musical instruments?

The large flat piece of wood in a piano, called the soundboard, amplifies and resonates the vibrations produced by the strings when they are struck. This amplification process is similar to how a soundboard functions in other Musical Instruments, such as Guitars or violins, by enhancing and projecting the sound produced by the instrument.