Here's why:
* Titles are proper nouns: Titles of books are considered proper nouns, like names of people and places. Proper nouns are always capitalized.
* Distinguishes them from other words: Capitalization helps distinguish a book title from the surrounding text and makes it clear that it is a specific, named entity.
Examples:
* *The Lord of the Rings*
* *Pride and Prejudice*
* *The Hitchhiker's Guide to the Galaxy*
* *To Kill a Mockingbird*
Exceptions:
* Short words in titles: Words like "a", "an", "the", "and", "of", and "for" are generally not capitalized in book titles unless they are the first word.
* Prepositions and conjunctions: These words are typically not capitalized unless they are the first word of the title or are particularly important.
For example:
* *The Great Gatsby*
* *Gone with the Wind*
Note: If the book title is within a sentence, you may need to adjust the capitalization rules slightly:
* I'm reading *The Catcher in the Rye*.
* Have you read *The Adventures of Huckleberry Finn*?
Remember, these are general rules, and there might be exceptions depending on the style guide you are following.