When you add an account to Zapier for an app or tool you use, such as Typeform, you create an app connection. This allows you to use the app account in your Zaps. By default, these connections are private, so only you will be able to use the app account in Zaps.
Sharing an app connection makes it available to everyone with who it's shared. This allows them to create Zaps with the app account without needing your login credentials to that app.
App connections can only be shared in Team or Company accounts. In Team accounts, you can share app connections with specific users in the account, or with everyone. In Company accounts, you can share app connections with individual users, teams, and all users in the account.