Some time ago i wrote an article to explain the licensing in Skype for Business Server and Skype for Business Online [The Skype for Business licensing guide], with the change to Teams i want to give you some insight in this licensing to:
Users in Teams (base license)
Every user that want to make use of Teams needs a Teams license.
Using your organization’s logo and custom color schemes to provide a consistent look-and-feel on your Azure Active Directory (Azure AD) sign-in pages.Your sign-in pages appear when users type in their sign in to your organization’s web-based apps, such as Office 365, which uses Azure AD as your identity provider.
Some people maybe notice where this background is from, for the ones that don’t know this is from Mr Robot.