Below are the different ways to add documents to a library:
1. Create a new document in the library via the New Document icon on the Ribbon.
2. Upload a single document by clicking the Add New Document link within the library.
3. Upload a single document by clicking the Upload Document icon on the Ribbon.
4. Upload multiple documents by clicking the Upload Multiple Documents icon on the Ribbon. This will open up the Upload Multiple Documents dialog box. You can drag and drop the files or browse the file system for them.
5. Save a document to the library directly from a Microsoft Office client application.