Big, powerful, 220 v 3HP, spindles up to 1", cutters come with holes in the center for different size arbors, can be stacked or inverted, cutters are expensive compared to router bits, rotation can be reversed, much more quiet, made for production runs with long run times, have induction motors...heavy duty and you have a choice of 2 speeds, 7,000 RPM and 10,000 RPM, designed for edge work, up to 4" thick, but cannot be used in the center of a panel.
Routers in a table:
Home shop size and weight, 1/2" or 1/4" collets, many variations of bits, from small round overs to large panel raising, no reversal of rotation, noisy AC/DC motors, not designed for continuous duty, but can be abused somewhat, variable speeds if you get the good ones, 8,000 to 22,000 RPMs, best fitted with a height adjustable "lift" for easier and precise bit height, the bit can be raised into the bottom of the work piece at any point in the panel or an edge. http://jessem.com/MAST-R-LIFT_II.html
Good, well equipped shops have both, maybe several of each to avoid changing out the bits or cutters. JMO