It is a medical speciality that uses special equipment and techniques to either find or treat a perticular condition. It is performed in case of an injury or disease. There are two types of surgery — elective and emergent. An elective procedure is one where the doctor and the patient decide before hand that a particular surgery needs to be performed. A surgery is performed by a trained surgeon, and usually the physician who performs the surgery is trained in that particular field. While open surgeries are still performed for complex cases there are a number of procedures that can be performed using minimally invasive techniques. It is important for a patient to know what type of surgery they are opting for and the risks involved.