A dictionary can contain thousands of words; however, the keywords in it are what give it meaning. When people use a dictionary, they are searching for the meaning of a word or phrase rather than the exact spelling or grammar. One would not search for the definition of “dog” in a scientific or technical dictionary; rather, one would look up the usage of the dog in the dictionary. Likewise, when people use a dictionary to look up keywords, they are not looking up the exact spelling or grammar, but they are looking up meanings of selected keywords. In the same way, a keyword in a bibliography is different from a keyword in an index or dictionary and therefore the two are used differently.