What Are Windows “Libraries” and How Do They Work?

Confusing is what they are.

Libraries were added to Windows 7 and persist to this day, though they're not as obvious as they once were.

In my opinion, libraries do little more than add confusion. I avoid them.

However, it's an interesting feature that can be useful if you understand what they are and are not.

Let's work on that understanding.

Understanding Windows Libraries

Windows Libraries, introduced in Windows 7, pull multiple folders into a single view for convenience. They can be confusing because they’re not actual folders but a virtual view. While useful for organizing, they require proper understanding to avoid issues. They’re safe to ignore entirely.

Viewing Libraries

Libraries were in your face in Windows 7, but not in Windows 11. In fact, in Win11, you need to make them visible before you can use them.

Run Windows File Explorer, click on the ellipsis in the toolbar, and click on Options to bring up the options dialog.

Click on the View tab, scroll to the bottom of the list, and make sure Show libraries is selected. Click OK.

A "Libraries" item will be added in the left-hand pane.

Click on that, and you'll see the four default libraries: Documents, Music, Pictures, and Videos.

What Libraries are

I'll probably say this repeatedly: Libraries are not folders, even though they kind of act like folders.

A Library -- say the "Music" Library in default installations -- is a view of one or more folders.

Right-click the Music Library and click Properties. You'll get a dialog much like this:

It remains unclear and confusing, but what this is telling us is that the Music Library contains a single folder: the "Music" folder associated with your login account. Its location is not shown (which adds to the confusion) but that folder is C:\Users\<login ID>\Music.

Clear as mud.

It'll get clearer if we click on Add... and add a second folder to the Library.

There are now two folders in the Music Library:

• C:\Users\<login ID>\Music (aka "Music") -- the default folder associated with your login account
• C:\MyPrivateFolders\Music -- a folder of my own I created

So far so good. But what does this mean?

I'll create two more files: "A-File-In-Default-Music.mp3" in "C:\Users\<login ID>\Music" and "A-File-In-My-Private-Music.mp3" in "C:\MyPrivateFolders\Music".

Now we'll look at three separate locations in Windows File Explorer.

First, "C:\Users\<login ID>\Music":

Now, "C:\MyPrivateFolders\Music":

And finally, the Music Library:

The Library shows the contents of both folders in a single place. Note that while the Windows 10 or 11 Library above explicitly shows the folders in which the individual files reside, this was not always the case. Before, the files were listed as if the Library was a folder... which it is not.

That, in a nutshell, is all a Library is: a single view of the contents of one or more folders defined as part of the library.

Whew!

Confusion #1: Multiple copies of files

What happens if I mistakenly place a file called "A-File-In-My-Private-Music.mp3" into the default folder instead of that private folder?

The Library will show two files with the exact same name.

Since Windows 10 and 11 show locations explicitly, it's not much of a problem, but previous versions of Windows didn't. They just listed the filenames one after the other with no explanation of why there were two files with the same name.

Confusion #2: Where do files go?

We've established that a Library is not a folder, but a view or a way of looking at the contents of multiple folders. But you can sort of treat a Library like a folder. For example, you can copy files into the Library.

But if a Library is not a folder, where do the files get placed?

Let's look at the properties of the Music Library again.

Note that each of the two locations has a checkmark in front of it.

• The green checkmark indicates this folder ("C:\Users\<login ID>\Music") is the default save location. It's where files are placed when you save them to the library. This is probably the most important since it's what happens when you save a file.
• The green checkmark overlaid with a couple of people indicates this folder is the public save location. It's where files are placed when other users or guest accounts save them to the library.

You can designate any folder that's part of the Library as a default location.

With the configuration above, if I copy a file to my Music Library (say, by dragging and dropping it onto the Music Library icon), it'll be placed in the default save location, the "C:\Users\<login ID>\Music" folder.

Libraries can be useful

I don't want to completely bad-mouth Libraries; they can be useful.

For example, if I have multiple Music folders all over my machine – perhaps purchased from several sources -- it might be convenient to create a Library or update the existing Music Library to reference all those locations. That way, the Library becomes a one-stop location for accessing all of my music wherever it might be.