The very first vending machine was said to have been invented by Hero of Alexandria, a 1st century inventor. His machine accepted a coin and then dispensed a fixed amount of "holy water."

Basically, a vending machine is a machine that dispenses merchandise after a customer deposits money. Vending machines have a currency detector which determines if the money inserted is sufficient to purchase the desired item.

Common locations where vending machines are usually placed include: next to the entrances/exits, next to the water fountain, in front of the restroom, in the break room, by the coffee maker, next to the other vending machines, by the receptionist, next to the cash register, next to the listening station at a music store, next to the change machine or in the waiting area.

The items sold in vending machine vary. In the U.S. vending machines may even carry alcoholic beverages such as beer and cigarettes. This practice is increasingly rare though, due to concerns about underage buyers. I

n Japan, there seems to be no limits to what is sold by vending machines. These include: drinks and cigarettes, bottles of wine, cartons of beer and pairs of underwear. Japan has the highest number of vending machines per capita, with about one machine for every 23 people.

Vending machines are classified mainly according to the products it carries. Below are just some of them:

Newspaper vending machines

With newspaper vending machines, a customer could open the box and make off with all of the newspapers after paying for one. Such assumes that the customer will be honest.

Candy vending machines

Candy vending machines are mechanical machines that vend a handful of candy, a bouncy ball, or perhaps a capsule with a small toy or jewelry, for one or two quarters.

Soda snack/vending machines

Soda/snack vending machines are, as the name suggests, sell cans or bottles of soda and/or small packages of snacks. For operators, soda/snack machines have the advantage that many locations recognize their need for such machines.

Specialized Vending

Specialized vending machines are those that dispense personal products, typically in public toilet facilities. These vending machines are often found in toilets used by transient persons in high traffic locations, such as bus stations and truck stops.

The machines in ladies restrooms typically sell sanitary napkins, tampons and tissue paper. In mens rooms, the vending machines contain tissue paper, cleansers and sometimes condoms.

These vending machines use a spiral kind of mechanism to separate and to hold the products. When the machine vends, the spiral turns, thus pushing the product forward and falling down to be vended.

Most vending machines are designed as large safes. They have also been extensively tested and designed to inhibit theft. Like any machines, vending machines are susceptible to malfunction. The causes are many-fold.

Coin acceptors often jam up, especially if a child inserts a bill or other foreign object into the coin slot. Bill validators sometimes falsely reject a legal tender bill that happens to be crumpled, ripped, or dirty. Vending machines usually have a phone number that angry users can call for service.

One of the newest vending innovations is telemetry, which is made possible by the advent of reliable, affordable wireless technology. With telemetry, data can be transmitted to a remote headquarters for use in scheduling a route stop, detecting component failure or verifying collection information.