Keyboards are amazing - they can recreate the sounds of hundreds of different instruments at the touch of a button. Want the sound of a concert grand piano? No problem - just select it from the control panel. But to really make a grand piano, violin or any number of other sounds come to life, you need something called Touch Sensitivity.
On a real grand piano, pressing a key harder will make a louder sound; on a violin, bowing harder will make the note louder; on a snare drum, hitting the snare harder will make a louder sound.
This sensitivity is so fundamental to music and the ability to put expression into music, that we can forget it's there - but not all beginner keyboards feature sensitivity.
The PSR-E353 does. Thanks to its fully touch-sensitive keys, you can perform with all the expression you desire - making it a natural step when you upgrade to a digital piano in the future.