A signal is said to be energy signal if it has finite amount of energy.
A signal is said to be power signal if it has finite amount of power.
Energy is a measurement of total strength, just like fuel.
The longer you measure the consumption, the more usage being clocked.
Like our home energy/water meter.
You might at one moment want to measure the consumption
from time 3sec to time 40sec.
The result is the energy that is used for this time period.
If you want to measure the total energy used,
we integrate from -infinity to infinity.
In practise integrating -infinity to infinity,
the contexts is not so clearly define.
Power is the rate of energy consumption.
Power = Energy/1sec
You can think of it as the average energy used for 1sec period.
Useful for projecting the energy consumption over a period of time.
Which is why equipment rating is in wattage.
We don't know how long we will turn on the equipment.
The longer you turn on, the more energy you use.