Is data that is collected by Meta pixel (and other tracking tools) shared with the entire Meta business user base or just the advertiser that collected it?

Have been trying to find and answer to this, but have not found a clear and unambiguous answer.

For example: if I add my email and address into a web form, and it’s captured by Meta’s pixel, presumably that is fed back to Meta.

But is it only available to the business that created the pixel? Or is it accessible for matching by every Meta Business user? (I’m not suggesting Meta Business users can identify an individual, but it would …

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