Market orders are executed at the best available price at the moment of purchase. Therefore, the assets are added to your Invest Pocket immediately after its execution.
In contrast, limit orders are executed only when the stock/ETF reaches your specified purchase price, and the funds are debited when you place the order. The positions are added to your portfolio only when the stock/ETF hits the price you're willing to pay. Kindly note that limit orders are valid for one day, and if they're not executed, the funds will be returned to your money pocket.