The tone curve is by far one of the most versatile, efficient, and powerful adjustment tools in Lightroom, and mastering it can take you a long way to better image edits and more creative control. If you are unfamiliar with the tool, this fantastic video will show you not only you can use it to adjust things like shadows and highlights, but how it can also be used to color grade an image.
Coming to you from Saurav Sinha, this excellent video will show you how Lightroom's tone curve tool works and how to use it for better image edits. The tone curve is simply a graphical representation of input and output luminance values. The horizontal axis represents all the luminance values currently in an image, while the vertical axis represents the values you would like to map the inputs to. This allows you to very quickly change things like brightness and contrast. But beyond those adjustments, by manipulating the tone curves for the individual color channels, you can quickly and easily color grade an image, remove color casts, and more. They are a tool every photographer should know how to use, regardless of genre. Check out the video above for the full rundown.
If you want to continue learning about Lightroom, be sure to check out "Fstoppers Introduction to Adobe Lightroom: The Ultimate Crash Course With Pye Jirsa!"
Excellent video Saurav!