As per Microsoft Teams Admin Center: “Guest access in Teams lets people outside your organization access teams and channels. When you turn on Guest Access, you can turn on or off features guest users can or can’t use. Make sure to follow the steps in this checklist to set up the prerequisites and so team owners can add guest users to their teams.”
As per Microsoft Teams Admin Center: “External access lets your Teams and Skype for Business users communicate with other users outside of your organization. Learn more
Your users can add apps when they host meetings or chats with external users. They can also use apps shared by external users when they join meetings or chats hosted externally. The data policies of the hosting user’s organization, as well as the data sharing practices of any third-party apps shared by that user’s organization, are applied.”
As per Microsoft SharePoint Admin Center, “External sharing” is the same as “External access” in Teams.
Guest Access vs Exteral Access
Microsoft: “Both guest and external access can be used at the same time in Teams meetings. If for compliance and security reasons, you want to limit access to Teams resources, you should consider using external access. With guest access, you do have the capabilities to specify the level of restrictions to meet your compliance and security obligations.” 🙁 – even more confusing…
This might help:
Microsoft: “External access enables access permission to users of an entire external domain. External access is a type of federation that allows users to find, call, chat, and set up meetings with people in other organizations. Guest access gives access permission to an individual. Guest access allows a user to invite people from outside your organization to join a team. Invited people get a guest account in Azure Active Directory.”
Teams vs SharePoint
When it comes to to collaboration with guests, Microsoft recommends Teams:
Microsoft: If you need to collaborate with guests across documents, tasks, and conversations, we recommend using Microsoft Teams. Teams provides all of the collaboration features available in Office and SharePoint with persistent chat and a customizable and extensible set of collaboration tools in a unified user experience.
- Microsoft 365 external sharing and B2B collaboration – Azure AD | Microsoft Docs
- Guest Users vs. External Users – Microsoft Tech Community
- Microsoft Teams Guest Access vs External Access – Which One To Choose – SysKit
- Microsoft: Use guest access and external access to collaborate with people outside your organization