Thread: martingale

I could not understand an importance of martingales?

I know mathematical definition of martingales, but I want to know their application in different branches.
I only know that martingale was gambling strategy, and also that it can be used in stock exchange.
I would be grateful if someone could explain me
Thanks

It's just a fair game, as opposed to super or sub-martingales.
You expect to be were you where based on past information.