After the printing press was invented, dictionaries with long definitions began to be called encyclopedias that were books that has articles or subjects For example, a dictionary of science, if it included essays or paragraphs, it was thought of as an encyclopedia or knowledgeable book on the subject of science. Some encyclopedias then put essays on more than one subject in alphabetical order instead of grouping them together by subject. The word, encyclopedia, was put in the title of some encyclopedias. 