Organization and Projects
An organization is the ultimate entity, an user with same email id can be part of mulitiple organizations, each organization will have its own subscription.
An organization can have multiple projects.
Billing happens per organization level. Each organization will have its own subscription.
To switch between different organizations which you have access to, you can click on the organization switcher on the top right header.
A project contains a group of monitors, status pages, analytics data and stripe data. Admins can create new projects in an organization. The billing/subscription happens per organization so there is no limit on how many projects can be created per organization.
To switch between different projects which you have access to, you can click on the project switcher on the left hand sidebar.