Self-service is the practice of serving oneself, usually when purchasing items. Common examples include many gas stations, where the customer pumps their own gas rather than have an attendant do it (full service is required by law in New Jersey, Oregon, and Richmond, British Columbia, but is the exception rather than the rule elsewhere). Automatic Teller Machines (ATMs) in the banking world have also revolutionized how people withdraw and deposit funds; most stores in the Western world, where the customer uses a shopping cart in the store, placing the items they want to buy into the cart and then proceeding to the checkout counter/aisles; or at buffet-style restaurants, where the customer serves their own plate of food from a large, central selection.
In 1917, the US Patent Office awarded Clarence Saunders a patent for a "self-serving store." Saunders invited his customers to collect the goods they wanted to buy from the store and present them to a cashier, rather than having the store employee consult a list presented by the customer, and collect the goods. Saunders licensed the business method to independent grocery stores; these operated under the name "Piggly Wiggly."
Self-service is over the phone, web, and email to facilitate customer service interactions using automation. Self-service software and self-service apps (for example online banking apps, web portals with shops, self-service check-in at the airport) become increasingly common.