Adjustment layers in Photoshop serve several important purposes: 1. Non-destructive editing: They allow you to make color and tonal corrections to an image without permanently altering the original file, preserving its integrity. 2. Precise control: With adjustment layers, you can fine-tune specific aspects of the image, such as brightness, contrast, color balance, and more. 3. Creative effects: They enable the application of various creative enhancements and effects to photos. 4. Stacking and combining: Multiple adjustment layers can be stacked and combined to achieve complex edits, offering more control over the final result. 5. Reversibility: Adjustments can be undone or changed at any time by toggling the visibility of the adjustment layer or deleting it altogether.