KERS - Kinetic Energy Recovery System - basically stores electrical energy under braking in batterys to be used as a 'boost' under power
Aerodynamics being the biggest change, front wings will be lower & wider and feature an adjustable plain that can be changed upto 2 times per lap, rear wings will be taller and wider, rear diffuser will be restricted in design also - I beleive this is to reduce the amount of dirty air so car behind can folow more closely
Bodywork will be heavily restricted - things such as barge boards, turning vanes, winglets, cooling chimneys & louvres, Shark fins on the engine cover will be banned.