As an application admin, you are able to add different components into the application. A document library is the place to store files which are related to the current application. For example, in a project management application, you can use a document library to store all files related to projects and folders can help you manage files more easily.
Here is an example of a document library.
Create Folders
Using folders is a good way to manage plenty of documents. Click the "+Add" button on the upper right of the library, and select "New Folder". In the pop-up window, fill in the name of the folder, then click "OK" to create the folder.
Upload Files
To upload files, click the "+Add" button on the upper right of the library, then select "New File" or "Batch Upload":
New File: Upload a single file to this library.
Batch Upload: Upload multiple files at once to the library.
Select files from your local disk and upload them to this document library. You will see the upload progress window showing at the bottom:
More Options of Files
Click the option menu at the end of each file item, from the pop-up menu list, you can see more actions you can do on the file.
Rename: Click to rename the file.
Edit: This is to edit the seleted item information. When you click Edit, the editing form will be popped up.
Pro tip
You can customize the list form to control what can be edited.
Copy to: Copy the file to another folder.
Move to: Move the file to another folder
Download: Download the file to your local disk.
View: Open the file on the browser.
Detail Info: Check the item information. Note, this is not to check the file content, just the item information. You can Customize the list form to determin what can be viewed.
Copy Url: Copy the item Url. You can send this Url to another user in your organization, and he or she must login before checking the item.
Delete: Click to delete the current item.
A document library is actually a specific type of data list, you can manage its columns, forms, workflows, notifications etc as the same you did for a data list.