I have an app (ASP.Net Classic) that is using Azure AD authentication. Now, we want to allow user outside of the organization to sign in. I read few document B2C and B2B, but I am unable to see which one to good for me.
I am looking that members in the organization should sign in and doesn't have to create new account. One of the option B2B suggested that to add user to in AD as a guest user but this is the manual process, it would be good if it can be automated. Also that doesn't describe how user would send the request to for login info.
It depends on your use case.
Imagine a large company. They have Azure AD for their employees. Now they want some suppliers to have access to their billing system. Those suppliers are guest users. That's B2B.
For guest users, an admin can send an invitation email that contains a redemption link.
B2C is for the customers of the company. They use the company's e-commerce system. They do not need access to the billing system.
B2C is self-service i.e. these users self-register and can change their profile or reset their password.