Min Cart or Drop-down cart of Magento gives a quick overview of the products which have been added into the cart. The trigger for this cart is placed within the main header. It is available throughout the site, regardless of the page user is currently on.
Many e-commerce stores don’t go for this type of functionality. Generally, when the user clicks on the cart button, they get landed to the cart page of the website. But a mini-cart is also a very handy feature. When the users need to remind themselves of what they have already added in the cart, they need to frequently check the cart. For this, it is very useful. It is mostly required in grocery stores, daily needs stores, where the customers can check whether they have added products to their bucket list or not.
It can also act as a feedback signal once the customer adds any product in the cart. Instead of cluttering the interface design with success messages (or modals) that confirm a successful cart addition, you can simply trigger the mini-cart to show!
Apart from showing products in the cart, the mini-cart should also provide the way to use to reach the full cart details page. You can also include a payment or checkout page so that the users can directly checkout as well.
Product manipulation is also possible with mini-cart functionality. Just like the cart page, the customer would be able to edit or configure the products.