Hello @Test Admin1
Thanks for reaching out!
As per my understanding, drive represents a user's OneDrive or a document library in SharePoint. For a licensed user resource, there is only a single drive.
Multiple drives are common when you are working with resource types other than "user". Using drive resource, you can get a user's OneDrive, Get the document library associated with a group, Get the document library for a site.
You can refer to driveType resource in API response. It describes the type of drive represented by a resource. OneDrive personal drives will return personal. OneDrive for Business will return business. SharePoint document libraries will return documentLibrary.
Refer this documentation for more details.
Hope this helps.
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