What is the purpose of a flint in a zippo lighter?

I recently bought a Zippo Lighter a few days ago and I have no experience with them as I usually use butane or disposable lighters. I know how to refill fluid into my Zippo but I don't know what the Flint is used for and when I should replace it...|||The flint is what creates the spark to light the flame, if your fluids full and and it still wont light, it's time to replace the flint.|||The flint is use to make the spark that your lighter needs in order for the fluid to light up. Your lighter will stop making a spark when it's time to replace the flint.|||to fuel the wick