Masticating juicers, like the Champion, chew fibers and break up the cells of vegetables and fruits. Generally, these give you more fiber, enzymes, vitamins and trace minerals, evident in the darker, richer color of the juice, and the sweeter, richer, fuller-bodied flavor. They have a toothed shaft that spins to masticate.
Grating juicers work in the same manner as masticating juicers, with similar results. They are only slightly less efficient at breaking up the fibers. They have a heavy metal toothed disc that spins to grate.
Pulverizing juicers, like the VitaMix, are very powerful blenders that break up and contain everything put into them. Their juice is heavier, thicker, and contains the fiber of the entire fruit. You may need to add water in order to drink this juice.
Squeezing juicers press out juice from citrus fruits. The size of the juicer cone will determine if the smallest lime or the largest grapefruit will fit properly. Needless to say, electrics work faster.