Capacitance and Voltage

This week in Physics we learned about capacitance.  A capacitance is energy stored.  It is the storage of lots of voltage but not a great deal of charge.  Some examples of of capacitance are keyboards and touch screen devices.  Let me try to relate my typing on this computer to this unit of physics that we are learning. The equation of a capacitance is C=(EA)/d [where C is the capacitance, E is the epsilon or permitivity of (air) free space, A is the area of plates (meters squared), and d is the distance between the plates (meter).  Every time I hit a key to type a letter, the capacitance changes because the distance between the two plates change.  The units of capacitance are Coulombs (Q)/Volts (V), also known as Farads (F).  This is what I learned this about in Physics this week.