Sheaf (mathematics)

A sheaf is like a stack of extra-large books lying in a pile. Each book is filled with different kinds of information. For example, the first book might be about weather, the second book could be about plants and animals, and so on. Each book is split up into chapters, and each chapter is divided into pages. Every page in the book has a bit of information related to its subject. When you look at the sheaf, you can see all the books, chapters, and pages, but you can't see the individual information within the pages. That's why it's called a sheaf: it's like a bundle of information.