Capacitance is resistance (not ohms) to a change in voltage using stored charge. The differential equation of a capacitor is dv/dt = i/c. This means that the rate of change of voltage is directly proportional to current and inversely proportional to capacitance.

touch screen capacitive works by the capacitance differential between the screen and your finger wherever there is difference in capacitance on the screen is where you are touching and the screen knows what function you are trying to do depending on what is displayed on the screen.

because of the coupling between the two transister and absence of capacitance it can amplify both dc and ac

Capacitance in mosfet is of three types:

gate capacitance

diffusion capacitance

routing capacitance

Gate capacitance: limits the speed of the device t which it can be operated

Diffusion capacitance: It is the capacitance due to charge carriers between drain and source.

Routing capacitance: It is the capacitance of the metal which is deposited on the top of oxide layer.

1. Transition capacitance

2. Diffusion capacitance

3. Space charge capacitance

4. Drift capacitance