The Batman of Arkham Knight is established as a polished and well-equipped vigilante. You add more Gadgets and techniques to Batman’s Utility Belt as you progress, but the Dark Knight is incredibly powerful and riding in style with the Batmobile very early on. At the start, Batman is carrying Batarangs, Remote Controlled Batarangs, the Batclaw, Explosive Gel, Line Launcher, Smoke Pellets, and (very shortly into the adventure) the Batmobile Remote.
You discover new Gadgets at certain parts of the main story, while Gadget upgrades, new combat techniques, and Batmobile customizations can be purchased using WayneTech Upgrade Points. WayneTech points are essentially XP, and you earn them by completing story missions, side missions, and by collecting Riddler trophies.
Gadgets supplement Batman’s fighting and movement, and certain Gadgets are required for puzzle solutions.
It’s the expert use of a wide array of specialized Gadgets that allows Batman to appear prepared for any contingency.