Porto Tolle, (IT)
Jigging is the fishing technique where an angler fishes a metal lure, called a jig, vertically. This is opposed to spinnerbaits which move through the water horizontally. Basically, a metal lure is dropped to a certain depth (normally the bottom) and then reeled in with rhythmic, jerky moves to attract the predator.
For jigging you can use both spinning and conventional reels. The line should be braided because it has less stretch. Jigging rods are short (less leverage and less fatiguing) and should have the ability to properly work a jig. There are a ton of different types of jigs ranging from long blades, wider jigs for slow jigging, center balanced jigs, inchiku, etc.
Jigging can be done anywhere in the world to find fish in deeper waters. For extreme jigging, you might want to have a look at Madagascar, Cape Verde, Seychelles, Maladives, Mexico, Florida Keys...