A document library provides a secure place to store files where you and your co-workers can find them easily, work on them together, and access them from any device at any time. For example, you can use a document library on a site in SharePoint Online to store all files related to a specific project or a specific client. Adding files or moving files between folders is as easy as dragging and dropping them from one location to another.
The default site in SharePoint Online includes a document library. You can add additional document libraries to a site as needed. This is useful, for example, if you need to restrict access to a set of files. Each document library displays a list of files, folders, and key information about each, such as who created or last modified a file. You can use this information to organize your files and make it easier to find them.
In a document library, you can:
- Add, edit, delete, co-author, and download documents.
- Control who has access to a library, a folder with in a library, or an individual file within a library.
- Track the activity on a file, such as when it was last modified, and receive a notification when something has changed.
- Create a custom view of a document library
- Share files or folders with others.
- Add a link in a document library to something that is stored outside the library, for example, a link to a file located in a different library or even a link to an external web page.
- Highlight a link, file or folder in a document library so you and others can get to them quickly.
At the top left of the document library page is the main menu.
Here you can create a new folder, document, or a link to something that is located outside the document library.
Alternatively, upload a folder or files.
You can also sync files with the new OneDrive sync client or create an alert to receive a notification when something has changed.
At the top right of the document library page, you can change the document library view to either list view or grid view. If using Internet Explorer, you can open the document library in Windows File Explorer, by clicking View in File Explorer.
You can add new columns and select the columns to display by clicking 
on the far right side of the column headers if you are in list view or, if you are in grid view, by clicking 
and then clicking on the far right side of the column headers.
You can view and edit information about a file or folder in the information pane, such as required properties, recent activity or whom a file is shared with. To show or hide the information pane, select a file or folder and click 
on the right-hand side of the main menu. You can also view the information pane by right clicking a file or folder and selecting Details.
When you select a folder or file, the menu at the top left of the document library changes to a list of actions you can perform on that folder or file.
You can see another version of the document menu by right clicking the file name or, if in list view, by clicking next to the file name. This menu contains additional actions such as Pin, which highlights files so you and others can find them quickly.
Ready to start?
Here are some additional help articles to get you going: