What is Levels in Photoshop?
This is a bit tough to explain. There is one slider with three control points named as A, B, and C in the below image.
A: Drag it to the right to increase the black
B: Drag it to the right to increase contrast and drag it to the left to decrease contrast
C: Drag it to the left to increase white
To make things simpler, Photoshop provides presets also which are highlighted with blue rectagnle. You may want to use it.
What is Curves in Photoshop?
If you see the graph, the y-axis is divided into 4 parts. Each part represents a region. Upper parts demostrate the light and lower parts demostrate the shadow.
- Highlight: It affects only the upper regions
- Light: It mainly affects the upper two regions but slightly affects lower two regions as well
- Darks: It mainly affects lower two regions but slightly affects upper two regions as well
- Shadows: It only affects lower two regions