dual InBoxes, Global and Local? confusing

I’m confused about these dual InBoxes, Global and Local They have an identical number of emails, seemingly mirrors of each other. Is that expected? Or am I just inadvertently doubling the database size? Fix?

Also, anomalously to me, the Global Inbox shows 109 emails total but 131 Unread.

Global folders are virtual folders containing messages from all your accounts. If you have set only one account then Local and Global folders are identical.

Count of unread messages includes all subfolders, not only the Inbox.