The Dodge, Burn, and Sponge tools are all tools that are used to make adjustments to the brightness, contrast, and saturation of an image. Here's a brief explanation of each tool:

Dodge tool: The Dodge tool is used to lighten specific areas of an image. When you use the Dodge tool, you can choose a brush size and strength, and then paint over the area of the image you want to lighten. This tool is often used to brighten up shadows or bring out details in an image.

Burn tool: The Burn tool is used to darken specific areas of an image. When you use the Burn tool, you can choose a brush size and strength, and then paint over the area of the image you want to darken. This tool is often used to deepen shadows or create more contrast in an image.

Sponge tool: The Sponge tool is used to adjust the saturation of an image. When you use the Sponge tool, you can choose a brush size and mode (Saturate or Desaturate), and then paint over the area of the image you want to adjust. This tool is often used to make colors more vibrant or to create a more subdued, desaturated look.

All of these tools can be very useful for making specific adjustments to an image, but it's important to use them with care and subtlety to avoid making an image look over-processed or unnatural.

Also remember these are DESTRUCTIVE tools meaning your image is altered.  The effect can be achieved non-destructively using different techniques.