Azure Active Directory Business-to-Consumer, also known as Azure AD B2C, is an identity management service that offers organizations the ability to customize and control how customers interact with corporate applications. It allows organizations to control how users sign up, sign in, and how they manage their profiles when using the applications. Azure AD Business-to-Consumer enables this functionality while also protecting customer identities. Applications registered with Azure AD B2C can be configured to handle many identity management tasks. 

For example, you can allow users to sign up to use a registered application, you can enable a signed-up user to edit his profile, and you can even enable MFA in the application. Other identity management tasks that can be handled include allowing users to sign up and sign in with specific identity providers, such as Facebook, for example. You can even customize the look and feel of the signup experience for users, as well as the sign-in experience. Azure AD B2C completes identity tasks by interacting in sequence with identity providers, also known as IdPs. It also interacts with users, other systems, and with the local directory. The Identity Experience Framework establishes multi-party trust and completes these steps. Along with a Trust Framework policy, this framework defines the actors, actions, protocols, and sequence of steps that need to be completed in order to make things work. Azure AD B2C makes use of SYN cookies and rate and connection limits to protect against denial-of-service and password attacks against applications. It also includes mitigation for brute-force password attacks, as well as dictionary password attacks. 

A service that authenticates customer identities and issues security tokens is called an identity provider. Azure AD B2C offers the ability to configure several different identity providers in the tenant. Common identity providers include Microsoft accounts, Facebook, and even Amazon. Before configuring an identity provider in an Azure AD B2C tenant, the application identifier, client identifier, password secret, and client secret, or a combination of each, depending on the identity provider itself, must be recorded from the identity provider application that is created. This identifier information is then used to configure the application that will be accessed via the identity provider being configured. Every Azure AD B2C tenant is distinct and separate from other Azure AD B2C tenants. To leverage the features of AD B2C, you must deploy a B2C tenant, and link it to your Azure subscription. If you wish to allow users to sign in to an application using Facebook, Amazon, or some other identity provider, you must first register the application in the Azure AD B2C tenant.