Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search is conducted over. These include mountain rescue; ground search and rescue, including the use of search and rescue dogs (such as K9 units); urban search and rescue in cities; combat search and rescue on the battlefield, and air-sea rescue over water.

Source: Wikipedia