Question

the power and voltage rating of an electric heater is 1000 watt and 220 voltage what does it mean

Answer 1

it means that heater will dissipate 1000 watt of energy on every 220 volts of supply

Answer 2

The unit of power is Watt. If the electrical heater is 1000 watt, that means for one hour the heater is going to use 1000 watt electricity also called as 1Kilowatt. If such appliance is being used for 20 hours per month and , the electric charge is going to be 20x rate per unit. Assuming rate per electric unit is Rs 5, the bill is going to be 20x5=100.

All electric equipment has power rating to let customer know how much power it is going to consume.

Voltage on the other hand is like pressure of water( called electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. )

In short words while voltage is like pressure of water, power is like amount of water consumed.

Hope it clarifies your doubt.