Answer:
Dictionary - definitions, pronunciation, and spelling of words
Encyclopedia - a collection of informative articles about a wide variety of topics from around the world
Online search engine - information stored in databases and on sites
Thesaurus - words with similar meaning listed together
Explanation:
Dictionary is usually a book filled with all kinds of words how to pronounce them and what they mean, a encyclopedia is a book that contains articles of just about anything you need to learn about in the world. A online search engine are things like Safari or Firefox where you can search a question and their databases can pull up a variety of results based on that question. Then a thesaurus are words with similar meaning shown together to show the difference.
Hope this helps.