Chapter 4: The Basics and Evolution of Authentication

In the previous chapter, we covered the different application types that can use Azure AD for authentication and looked at user consent. We covered public client and confidential client applications, how application sign-in flows work and the different application types, such as web apps and APIs, deamon apps, and more. Next, we built a web app that authenticates users using Azure AD. Finally, we covered how users consent to applications and looked at publisher verification.

In this chapter, we are going to take a step back and look at the basics and evolution of authentication. This chapter will not contain code samples; instead, it will look at how authentication has evolved into the modern authentication protocols that we are using right now in our applications.

We will start this chapter by explaining how identity protocols evolved. After that, we will look at the difference between authentication and authorization. Then...