Books have been highly important to me, not only as a means of information and entertainment, but also for the shared language they offer and the function of that language for different communities and relationships in my life. Books (in particular narrative works of fiction) provide an entire shared world, meaning, and language for those who have read them.
Here is one example. As a young person I attended a summer reading course. We read many books together, including Jonathan Livingston Seagull, by Richard Bach, and the scipence fiction classic Stranger in a Strange Land, by Robert Heinlein. As the summer months progressed, we developed a shared lanuage based on these books. We communicated using words and slang only found in the books. The language of the books became our own secret language. In this way, books have not only served as a personal gate of entry to new worlds, but have also served to connect me with others through the shared reading experience.