How does particle system work?

Can anyone explain how particle system works ? Please help!!!

The official documentation can explain it much better than i could.

Please take a look here:

hey Gupta, you really need to learn how to use google.
Looking at your string of (odd) questions lately, here is how:

go to google.com

begin with “UE4”
then the subject: “Cascade” or “particle system”
Then what you want: “Tutorial”
or the problem at hand “Color over life”

so you google sentences like “UE4 Cascade tutorial”
so you get stuff like: LMGTFY - Let Me Google That For You

I also made some cascade tutorials you can check out here:

Thank you for your advice.