Highlighting and contouring is a way to cast light and shadow on areas on the face to achieve a 'natural' look, if you do it otherwise you may be doing it wrong, learn how to in this tutorial
Highlighting and contouring was made popular by Kim Kardashian and other Hollywood celebrities.
It was intended to achieve a chiseled and 'natural' looking facial features.
If done correctly, highlighting and contouring cast light and shadows respectively on the face to achieve a 'believable' look but a lot of ladies get it wrong or do it way too unnatural.
This video shows how to get highlight and contour done in few easy steps, watch the guide above.