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Capacitance (or capacitance) is a physical quantity that represents the capacity of a capacitor to hold charge. Capacitors from physics, it is a static charge storage medium, the charge may exist permanently, this is its characteristics, it is widely used, it is an indispensable electronic component in the field of electronics and power. It is mainly used for power supply filtering, signal filtering, signal coupling, resonance, filtering, compensation, charge and discharge, energy storage, DC isolation and so on
Charge is a physical quantity used to measure the amount of electric charge. In general, the charge quantity of a positive charge is expressed as a positive number, and the charge quantity of a negative charge is expressed as a negative number.
In the sentence of the subject, the first charge represents the amount of charge, the second charge represents the charge itself, and in most cases the two are easy to distinguish. When you represent the charge itself, let's say a positive charge, a negative charge like this. When you represent the amount of charge, say, a metal rod with a 30 coulomb charge. In physics, there will be a symbol for more than one meaning, such as W used to represent work done, or the unit of power watt. Just understand the logic. Don't worry about it.
Quantity Q= product of voltage U and capacitance C. Capacitance is defined as the amount of charge stored per unit voltage. Equivalent to the thickness or cross-sectional area of the bucket, the voltage is equivalent to the height of the water level in the bucket, and the water volume is the electricity quantity Q.