piano is an acoustic, stringed musical instrument invented in Italy by Bartolomeo Cristofori around the year 1700 
Wow, so the piano has been around for hundreds of years.
Yes,   It is played using a keyboard, which is a row of keys 
There have been some famous piano players from Mozart to Elton John nowadays.
The word "piano" is a shortened form of "pianoforte"
Sounds like a lot of piano related devices were Italian.
Yes,  The Italian musical terms "piano" and "forte" indicate "soft" and "loud" respectively, in this context referring to the variations in volume (i.e., loudness) 
I used to play piano as a child, and I always was fascinated with the Italian terms.
the greater the velocity of a key press, the greater the force of the hammer hitting the strings, and the louder the sound of the note produced and the stronger the attack
That makes sense that hitting the keys harder would make the notes sound louder.