What is a Meta Pixel?

Why it matters for agencies

Agencies usually need the Pixel shared separately from the ad account. Partner access can bundle the ad account, Pages and Pixel in one grant.

The short version

If you're an agency or a client trying to get set up quickly: a Meta Pixel (now a dataset) is a piece of tracking code on a website that records visitor actions and sends them to Meta for ad targeting, optimization and measurement. The practical takeaway is that you should never need to share a password to make this work — every major platform has an official way to grant access, and it can always be removed later.