Apple Aperture, Capture One, Adobe lightroom are geared towards processing of RAW files straight from digital camera. They are geared towards the photographer by providing tools for photo adjustments (saturation, curves, contrast, white balance etc...) as well as cataloging capabilities to keep track of photographs.
Photoshop Elements, CS, GIMP, Paint shop are geared towards the manipulation of digital images. You can brush, air brush, layer, mask, etc... these are generally geared towards the graphic artists.
WIth that said... it is common to see both RAW converters and photo editing software leveraged in a single workflow. In fact, most photographers I know, will do 90% of their work in a RAW converter (like Adobe Lightroom) and their final tweaks/adjustments in an editor like Adobe Photoshop.