Organizations explained
An organization is a collection of related accounts, projects, and resources. If you have a company, it translates well into an organization, so you can have your Shopify account and all related social media accounts under the same organization.
An organization can only access resources within the same organization, for example, if you have a project to post products automatically to social media, the project will only be able to access products within the same organization.
Shopify accounts
A Shopify account can only be connected to one organization at a time. If you have a Shopify account then it is important to plan your organizations around your Shopify accounts.
An organization is automatically created for you when you connect your Shopify account for the first time.
Meta (Facebook and Instagram) accounts
Facebook and Instagram accounts can only be connected to one organization at a time. If you connect a Meta account that is already connected to another organization it will be disconnected from the other organization.