Limit price you need to set a price, you can’t just click Limit and expect the order to fill. Market all you do is type in the volume you want to sell or buy and click Market and it will fill at the best bid/ask there is.

If price is $50,000 and there is a bid at $49999 and an ask at $50001. If you do a market buy, it will buy it at $50001 and not $50000 which was the last traded price. If you do a bid at $49999, it will only buy it at $49999 if someone market sells to you at that price.

Let me know if this makes sense. I can explain better if you are confused.