Is Parallax Mapping Still Used?

It's probably used more often than you're aware, just with more subtlety so it's more difficult to discern. Parallax mapping is fairly expensive to render, at least for the methods that work well, and shader complexity is probably the most common cause for rendering slowdowns in current tech. So it's often avoided.

How does parallax mapping work?

Parallax mapping is implemented by displacing the texture coordinates at a point on the rendered polygon by a function of the view angle in tangent space (the angle relative to the surface normal) and the value of the height map at that point.

What is parallax mapping payday 2?

"Parallax mapping is an algorithm for creating visual depth within 2D textures." taken from the overkill website.