Ulcer refers to any sore on the skin or a mucous membrane, but is commonly used to refer to a disorder in the upper digestive tract. There are many types of ulcers: oral ulcer(an open sore inside the mouth), peptic ulcer (an ulcer in the stomach) and genital ulcer(an ulcer located on the genital area).The terms ulcer, gastric ulcer and peptic ulcer are often used interchangeably. Peptic ulcers can develop in the lower part of the oesophagus, the stomach and the small intestines. Ulcers can also occur on the outside of the body and are called skin ulcers.
Attribution: Straight Talk Foundation