Why did we use a capacitor in this circuit?

[GIORGI]

I KNOW WHAT CAPACITOR IS. IT'S AN EQUIPMENT THAT SAVES ELECTRICAL ENERGY.
MY QUESTION IS THIS:
LET'S IMAGINE WE HAVE A CIRCUIT : BATTERY, A LIGHT, AND CAPACITOR. CURRENT FLOWS THROUGH ALL OF THEM. CAPACITOR IS TRYING TO SAVE ENERGY,ITS VOLTAGE IS INCREASING, AND FINALLY, WHEN IT'S FULLY CHARGED, A LIGHT gets switched off.
then,when this all happened, question is why did we use capacitor? what did it help us with? maybe I didn't want light to be switched off, but let's say I wanted it, then looking at this condition, what am i going to do with capacitor that has energy now?

 

[mgkii]

You wouldn't use a capacity in that circumstance.

Imagine a different real world scenario. You want to generate a really bright flash for a camera, you need a load of energy to get the flash to the level you need, but you don't want to design something that requires really big batteries. What do you do? You build a circuit that charges up a capacity over a period of time (could be a few seconds, could be longer) using small batteries, and when you get a full charge, you release it from the capacitor into the flash circuit and get the voltage required to make your flash really flash!

 

[tech99]

I KNOW WHAT CAPACITOR IS. IT'S AN EQUIPMENT THAT SAVES ELECTRICAL ENERGY.
MY QUESTION IS THIS:
LET'S IMAGINE WE HAVE A CIRCUIT : BATTERY, A LIGHT, AND CAPACITOR. CURRENT FLOWS THROUGH ALL OF THEM. CAPACITOR IS TRYING TO SAVE ENERGY,ITS VOLTAGE IS INCREASING, AND FINALLY, WHEN IT'S FULLY CHARGED, A LIGHT gets switched off.
then,when this all happened, question is why did we use capacitor? what did it help us with? maybe I didn't want light to be switched off, but let's say I wanted it, then looking at this condition, what am i going to do with capacitor that has energy now?

If you now remove the battery, and place a jumper in its place, the bulb will once again light for the same time. A useful energy store.