As you dig deeper into Lightroom or Photoshop you’ll begin to experiment with the tone curve.
It is an interesting tool and something you can use to really customize your photos.
The curve is an adjustment tool. It lets you drag a line to cause changes in your photo. As you drag the line around your changes will be shown in the sliders below the curve. You can also drag the sliders and see the effect on the tone curve. Basically it lets you change the brightness/darkness (luminosity) of the pixels.
The upper area of the curve controls the brighter pixels and the lower end the darker pixels. Bright and dark pixels are distributed throughout most photos. Bright areas have more bright pixels but may also have some dark ones too. That’s what provides texture and shadow. When you adjust the luminosity you adjust all the bright or dark pixels throughout the photo, lightening or darkening them. These adjustments will affect the entire photo and will be most noticeable in the bright areas or dark areas.
The curves tool also allows you to just adjust the red, the green or the blue pixels independently. If you lighten or darken the red pixels the neither the green or blue pixels will be affected.
Little by little as you experiment with the curves tool you’ll find yourself adjusting your photos better and better and gradually you will develop a look that is uniquely yours.