What is search and rescue?

I copied and pasted this from 'The free dictionary by Farlex' because i couldn't explain it clearly.

'The use of aircraft, surface craft (land or water), submarines, specialized rescue teams, and equipment to search for and rescue personnel in distress on land or at sea. Also called SAR. See also combat search and rescue; combat search and rescue mission coordinator; component search and rescue controller; isolated personnel; joint combat search and rescue operation; joint search and rescue center; joint search and rescue center director; rescue coordination center; search and rescue mission coordinator. '

Dictionary of Military and Associated Terms. US Department of Defense 2005.

Is this what you ment?