Here's a breakdown:
* Ancient Egyptian Papyri: These scrolls predate the book as we know it, but they contained written works, often religious or historical in nature. These could be considered "books" in a very early form, dating back to around 3000 BC.
* Clay Tablets: The earliest known written documents are inscribed clay tablets from Mesopotamia, dating back to around 3500 BC. While not bound together in a codex form, they contained information and could be considered "books" in a very basic sense.
* The First Codex: The earliest surviving bound book is the "Codex Sinaiticus," a copy of the Bible dating back to the 4th century AD. However, it's highly likely that earlier codices existed, but haven't survived to this day.
So, the "first book" is a complex question with no definitive answer. The earliest written documents and scrolls can be considered "books" in a broad sense, while the first bound codex with pages we know of is the Codex Sinaiticus.