Other Volumes In Disk Utility- What Are They?

[PGB1]

Hello,
I apologize if the answer is here, but I could not find it. On the general internet, so many different answers to my question (below) gave no definitive answer, so I thought the wise thing would to be asking here.

In Disk Utility, when I click on the hard drive, entries for "Other Volumes" appear. When clicking Macintosh HD, the space used is 87.86 GB. When clicking MacIntosh HD-Data, the space used by Other Volumes is 19.6 GB.

My curiosity is what these volumes contain & why they are present. I also wonder why one of them is so large.

Thanks For Explaining!
Paul

 

[MacInWin]

It's the way the boot drive is organized. Basically, from your images, you have a 1 TB drive that has one Container with two Volumes in it. One Volume is the System area. That is where the operating system and support files are located. The other Volume is Data, which is where the User files are located. When you select one, the other becomes the "other" volumes. The two share the free space on the drive dynamically. There is a lot more to it than just that, but for your question, that's the explanation. There are actually many more small areas on the internal storage, owned by the system. Don't mess with the drive or it can become unbootable.

 

[PGB1]

Thank You Jake for your excellent and easy to understand explanation. I hadn't noticed that the "other" switches back and forth depending upon which I click.

Thanks Again!
Paul