An order is an instruction to the exchange to purchase or sell an asset for you.
A market order is an order to buy or sell immediately a specified quantity of the underlying security.
if you are going to buy an asset, you will pay a price at or greater than the ask price in the ticker. If you are going to sell an asset, you will receive an amount at or lower than the bid price in the ticker.
A limit order, sometimes referred to as a pending order, allows you to buy and sell assets at a certain price in the future.
This type of order is used to execute a trade if the price reaches the price you decided. The order will not be filled if the price does not reach this level. In effect, a limit order sets the maximum or minimum price at which you are willing to buy or sell.
For example, you can create an order saying “I want to buy 1 bitcoin when it reaches 4,000$”.