Tone Mapping is a plugin by Photomatix who make software for HDR photography. HDR is High Dynamic Range, where you increase the contrast by taking at least 2 different exposures of the same scene to remove limitations to the digital sensor. Tone Mapping can be used on a processed HDR, or on a single image with an image editing program, to create the look of an HDR image.
To summarise it is not basic editing though, and isn't permitted under the POTW rules.