Raw files contain a lot more information than what is available once an image is opened into Photoshop. That means it is best to deal with overly dark or bright images and extreme color issues in Adobe Camera Raw (also known as ACR) before opening the images into Photoshop. Learn how to do that and much more in Zero to Camera Raw.
Meg seems to always nail her exposures and therefore can often make minimal changes in ACR, but that doesn’t mean everyone else should! Learning how to optimize your images in Camera Raw will allow you to rescue poorly exposed images and is often a more efficient way of adjusting your images than Photoshop. Adobe Camera Raw gets installed when you install Photoshop and now you can learn to get the most out of it!
Ben walks you through all aspects of ACR. A must have.