I searched hogs in both the World Book for Kids and the World Book Students.  The student site definitely had much more information.  From the parts of the hog, to different types of hogs, uses of the hog, charts that show leading hog producing states, etc.  The Kids section was pretty bare bone which I suppose you would expect for K-5.  I think the most useful part of this website for me will be the double clicking on words to get a definition.  I teach middle school social studies and the most common type of questions I get are asking to define a word.  I don't mind answering these, of course, but if a student can double click on the word right there and find out the meaning, all the better.  Especially for those who don't like to speak or be thought "dumb" if they don't know the meaning of the word.  I noticed that this option was available in both the kids and students version.