A smart vending machine is a digital terminal that takes in product position (row and column number) from a number pad/key or touch screen and then pushes the product to delivery chute . A ouput slot for excess change/notes and a card slot or coin insert/notes insert for payment. Behind the scenes - it needs to have a mechnism to count physical coins/notes(similar to an ATM machine) or process digital payments via bank card and render chnage and receipt on successful transaction . Validate user input - reply is product is available before processing/asking for payment etc. It most likely looks like a video games terminal in an arcade for me - the digital part has chipset - firmware-software stack and has wifi connectivity/plugged into wired network.