Reduce Quantity and Remove Items are among the various editing options you can enable or disable for your customers.
Reduce Quantity - This allows customers to decrease the number of items of a specific product in the cart but it cannot go below 1. Best used if customers typically make a mistake of adding multiple of a same item.
Remove Items - This allows customers to completely remove any item from the cart. If customers regularly make a mistake in the selected variant, this would be the perfect choice.