Like an individual, each piano boasts it’s own personality. The tone may differ ( i.e. a brighter treble, a mellow bass, “brassy” sounding bass, darker bass, dull treble, a tubby bass), touch ( i.e. heavy touch verses a light touch, responsiveness, do keys repeat quickly on staccato blow? which touch will affect). There are also the obvious areas such as various types of pianos such as grand, upright, spinet, studio and console.