A market order swaps speed for precision. The SEC sums it up: execution is guaranteed, the execution price is not. The order will fill, and it will fill fast. The exact price might drift a hair from what you saw on the screen when you clicked. That drift is slippage, and it can go either way.
This is the order type for moments when getting in matters more than the tick. Major news prints, session opens, fast exits when a setup is invalidated and you need out. Anywhere waiting a couple of seconds for a better price costs you more than just taking the position now.
Algorithmic strategies use market orders the same way a discretionary investor would: when the timing is doing the heavy lifting. A trend continuation signal that has already started running. A breakout happening right now, not three pips from now. A stop loss that has just triggered, and the only thing left is to fill it.
Javlot routes market orders to the broker without any added pause. The fill that lands in the broker history is the actual fill, slippage and all. Nothing is held back to make a fill look prettier than it really was. The number on the strategy page is the number on the broker statement.