When a car’s suspension is upgraded with lowering springs, the result is a lower ride height, a more aggressive look, and better handling due to the lowered center of gravity. While those things are great improvements for the car, the tires suffers from increased wearing and tearing since the tires will slant inwards towards the inside fender.
A camber kit will allow the car to remain at the lowered ride height while correcting the angle of the tire closer to the spec it was supposed to be.