How does Container Disk5 function in External Disk on MacBook Air?
when in the utility app, it shows Container disk5, then backup under it in the external disks. what is this?
[Re-Titled by Moderator]
MacBook Air 13″, macOS 15.3
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The current macOS uses a new drive format - APFS - vs the older pre-High Sierra OS which used HFS+ as the format. HFS+ and earlier formats used disk partitions to divide the space on the drive into chunks that could be named and referred to as volumes.
APFS sets up a drive with a container (partition) that manages the drive space. Within the container there will be the APFS volumes that you will see and interact with in Finder and on the desktop.
In this case of your external disk, Container disk5 is the partition and backup, indented below it, is the APFS volume.
• A container may have 0 or many APFS volumes within it.
• APFS volumes will always reside within a container.
• APFS volumes share the available space within the container and will dynamically grow or shrink as the number and size of the files they contain changes. This is all managed by the OS.
• Containers are named by the OS, but you define the name of APFS volumes you create.
• A drive that is formatted with APFS does not have to be repartitioned to create additional drive volumes. APFS volumes can be added or deleted more quickly than a drive can be repartitioned.
• An APFS formatted drive may still be partitioned, in which case each partition will have a defined storage capacity and a container within which its APFS volume(s) will reside.
• APFS was built to leverage the speed and tech of SSDs, but can also be used for HDDs.
The modern Mac is shipped with its internal startup drive formatted with APFS. The drive will have a single container, and within that container are usually five APFS volumes: Macintosh HD, Macintosh HD - Data, Preboot, Recovery, and VM.
When you erase and format a new drive, you will supply a name for it. That name becomes the name of the APFS volume that is created within the container on the drive. It is the name that Finder will display on the desktop and when navigating in Finder windows.
Disk Utility User Guide for Mac - Apple Support
Add, delete, or erase APFS volumes in Disk Utility on Mac - Apple Support