The concept of mark‐to‐market process for Futures

The concept of mark‐to‐market process for Futures in few lines: 

The mark-to-market is a process starts with depositing money (initial margin) in a margin account with the Futures Exchange while starting of the transaction of Futures contract.  

The margin account will remain open as long as the Futures are open.  

The margin account gets adjusted with change in Futures rates that is the profit or loss on the change in rates of Future. The change in futures price is referred a Tick (1 Tick = 0.0001, which is the smallest possible movement) 

A minimum balance needs to be maintained in the margin account by the investor company (maintenance margin). 

In case of there is loss due to change in price of futures and the margin account balance fall below minimum level (< maintenance margin) then the Futures Exchange may call for demand (a margin call) for depositing additional amount (variance margin) to bridge the short fall.