Cloudfare: what is it, how much does it cost?

Dear team
I hope you all have a great day.
I am brand new on services.  So far it’s very good.
I wanted to know: what is cloudfare (I mean: what are the benefits of having it in my current free account?).
And most important: does it have a cost for a free account?
Thanks for your help.
If you liked it(mostly users does) then enable it in your cPanel, then

Cloudflare is kinda free because it has a free plan that provides enough features, to be satisfied by using it.

Thanks MrJunior! I will check these out.