Use of big electrolytic capacitors in a DC/AC mains inverter

[abhishekkumar1902]

I was browsing some low freq transformer based DC/AC mains inverter circuits (like 12v DC to 220v AC) online and found a couple of designs having these big chunky electrolytic capacitors. This may sound a foolish questions but any idea exactly on which rails they use these big caps and why is it needed when the inverter is already using a DC source to drive your inverter? I am sure they're not used in any low pass filter circuit as the value of cap is pretty big is what I saw.

[strawberry]

It is low impedance power source

[abhishekkumar1902]

How does it helps?

[MagicSmoker]

An inverter draws pulses of current from its supply; the capacitors supply those pulses, minimizing the effect of any stray inductance in the supply wiring.