A library is a location on a site where you can create, collect, update, and manage files with team members. Each library displays a list of files and key information about the files, which helps people to use the files to work together.
You can create and manage documents, spreadsheets, presentations, forms, and other types of files in a library. The Shared Documents library is created for you when you create a new site. You can customize the library for your purposes, or you can create additional libraries.