Nearfield use would be listening in close proximity to the speakers themselves 3-6 feet. Typically for monitoring purposes. A very linear speaker is needed as well as being completely neutral (adding nor detracting from the original source) for making sure the sound is true to the source ( think studio applications). Imaging and staging are not overly critical in this type of application.
A realistic setup would be to replicate the event recorded. Linearity, accuracy, and neutrality are still extremely important, but now one would also desire good dispersion characteristics to allow the speaker to reproduce the image, space, depth and stage of the recorded event.
