What is the difference between a market order and a limit-on-close order?

@marion.bernhard 

A market order is an order to buy or sell a security immediately at the best available current price. It is executed at the current market price and guarantees execution but does not guarantee the price at which the transaction takes place.

On the other hand, a limit-on-close order is an instruction to execute a trade at the market's closing price, but only if it can be matched with a buyer or seller at that specific price or better. This order type allows traders to specify the maximum or minimum price at which they are willing to buy or sell a security at the closing auction. If the closing price does not meet the specified limit, the order may be canceled or left open for the next trading day.

The key difference between a market order and a limit-on-close order is that the former is executed immediately at the best available price, while the latter is only executed at the closing price or better, providing a level of price control for the trader.