This is a common point of confusion. Here is how the pieces fit together.
Understanding Meta Structure
Facebook Page
A Facebook Page is your business public presence on Facebook. It is where you post content, interact with followers, and build your community. Think of it as your storefront window.
Meta Business Manager
Business Manager is the back-office system where you manage all your business assets: Pages, Ad Accounts, Pixels, and team permissions. It is the control centre.
Ad Account
An Ad Account sits within Business Manager and is where you actually create and pay for ads.
How They Connect
Business Manager (container) contains Pages + Ad Accounts + Pixels. Ad Account uses Pages to run ads. Pixel tracks conversions from those ads.