A market order is a type of order which will execute instantly and fill your order with the best available price in the order book.
The disadvantage of a market order is that you’re not guaranteed a specific price you’re trying to buy or sell at. It all depends on what's available on the order book.
Let's take a closer look using the example below where the green orders being Buyers or Bids and the red orders being Sellers or Asks.
Once a Market Order to SELL ADA to CAD is placed. It triggers to sell right away to the first 2886.67 ADA available in the order book, in this case, $0.187 CAD. The order will keep taking from the orders below until the sellers quantity is fulfilled.
A Market Order to BUY ADA with CADis placed and it triggers to buy, the first 2172.5 ADA from the buyers purchase will be triggered at $0.194 CAD and will take consequently from the orders at a higher price until the position is fulfilled.
Note: All Market Orders are Subject of Marketing Adjustments