Drop Shipping is a type of business model which enables a company to operate without maintaining inventory, owning a warehouse to store their products, or even having to ship their products to their customers themselves.
You simply partner with a drop shipping supplier and list their merchandise for sale.
Once you receive an order you forward it to the supplier for fulfillment. The supplier will ship the product directly from their warehouse to your customer.
Your profit is the difference between what you charge your customers on your website and what your drop shipping supplier charges you.
This kind of business model is extremely attractive as it eliminates the need for the store owner to have a physical business location such as an office space or warehouse, instead, all they need is a laptop and an internet connection.