It is an economic model for the movement of prices in the financial markets, and to determine the price of any trading tool, it is necessary to know the bid and ask price. The laws of supply and demand are based on determining the relationship between the seller and the buyer. 

When the demand price exceeds the supply price, it is called the “demand zone” and this leads to an increase in prices, but if the asking price is less than the supply price, it is called the “supply zone” and this leads to a decrease in the price, so investors wait to determine their direction according to the current zone and enter into deals, whether Buying or selling after selecting the type of area “Bid or Ask.”