There are 2 Methods of Ordering Products.
2.Add to cart
Quick Buy is for Order any product Fast and quick, just click QUICK BUY button and fill up the Order Form and click PLACE ORDER. Thats it. (you can set Quantity as well i.e 1,2,3 etc)
Add to Cart is for when you have to shop more than 1 product, Click on Add to Cart button and then view your cart click on Checkout to fill up Order Form and click on PLACE ORDER.