Color grading is all about image stylization and your own personal preferences for your images. This video by Nemanja Sekulic is an excellent tutorial about how to put both Lightroom and Photoshop to use when color grading your portrait work.
There is a specific difference between color correction and color grading. Color correction is adjusting for color issues that were either overlooked in the field or were too much to try to correct while actually on the shoot. Instead of focusing on correction, color grading is all about using color to enhance, style, or otherwise give an image a specifically intentional look.
Image stylization is just one of many ways to distinguish yourself as a photographer from other artists. Outside of the lenses you use, the locations utilized, and choices in lighting, your choices in post-production can also be used to a very effective point. That point is simply to create a look that is unique to you and the images that you create. Whether you prefer a minimalist approach to post-processing, a more dramatic approach, or even a heavy digital artistry style, what you do with your images after the shoot is a part of your brand. Taking the time to consciously color grade your work, regardless to what degree you do so, is something that can enhance your personal style and help you become more recognized throughout the world.