Which tool allows for editing an image without losing the original data?

The Adjustment Layer is the tool that allows for editing an image without losing the original data. This feature enables you to apply changes such as brightness, contrast, hue, and saturation to your image non-destructively. When you use an Adjustment Layer, you are essentially creating a layer that sits above the original image layer, applying transformations that can be modified or removed at any time without affecting the underlying pixel data.

This non-destructive workflow is particularly advantageous for maintaining the integrity of the original photo, allowing for flexibility and experimentation. If adjustments need to be modified or eliminated, the changes can be easily altered by adjusting the properties of the layer or turning it off altogether.

In contrast, tools like the Brush Tool, Magic Wand Tool, and Clone Stamp Tool make permanent changes directly to the original image pixels. While they are essential for various editing tasks, they alter the original data, which means that once changes are made, they cannot be reverted to the original state without having a separate backup of the unedited image. This emphasizes why the Adjustment Layer is preferred for non-destructive editing processes in Photoshop.