Do u know...?

Hello everyone,
please do know which brokers use ‘Order Cancel Order’?
Secondly, what does hedging means during trading?

A hedge is an investment that is taken out specifically to reduce or cancel out the risk in another investment. In the currency market investors usually use correlated pair to hedge their risks.

You can find a lot of info in wiki:

Hedge (finance) - Wikipedia, the free encyclopedia

Currency correlation - Wikipedia, the free encyclopedia