A bookshelf is a piece of furniture with horizontal shelves designed to hold books upright. Most bookshelves have several shelves stacked vertically, creating rows where you can organize books by subject, author, size, or however you prefer.

Bookshelves come in many styles and sizes. A small bookshelf might sit on a desk and hold just your favorite novels, while a tall bookshelf might reach from floor to ceiling and hold hundreds of books. Libraries have enormous bookshelves that require rolling ladders to reach the top shelves. Some people use bookshelves to display more than just books: photographs, trophies, science projects, or collections of rocks and seashells can share space with the books.

Before printing became common, books were rare and expensive, so only wealthy people or institutions had enough books to need dedicated shelves. Today, a well-stocked bookshelf is like a window into someone's mind: you can learn what subjects fascinate them, what stories they love, and what they've been curious about over the years.