The Pancam is a panoramic imaging system that provides views in stereo and false color infrared wavelengths (green, red, infrared) of the surface around the rover. Spatial resolution is approximately 0.3 to 0.4 milliradians/pixel.
The Navcam is used to navigate the rover. It has better stereo precision because of a wider field of view, allowing it to image more in a single frame. Unlike the Pancam, it does not image in color.
The Athena Payload website contains more information about the Pancam flight model.