Trolling is a method of fishing where one or more fishing lines, baited with lures or bait fish, are drawn through the water. This may be behind a moving boat, or by slowly winding the line in when fishing from a static position, or even sweeping the line from side-to-side, eg when fishing from a jetty. Trolling is used to catch salmon in the greater lakes of Sweden and in the Baltic Sea.
Trolling from a moving boat is a technique of big-game fishing.
Trolling from a moving boat involves moving quite slowly through the water; this may be accomplished by use of a special trolling motor.
Many anglers troll for some or most of their fish. Trolling is the way to catch trout and salmon on lakes and sea.