With two-factor authentication (2FA) becoming increasingly important to protect web apps and services against fraudulent signups, implementing 2FA in Java web applications can significantly decrease the chances of unauthorized access. The tutorial guides users through the process of adding multi-factor authentication with Java, using SMS 2FA, which sends a text message with a verification code to the user's phone. The Verify API is used to send and verify the codes, providing an additional layer of security for user data. By following the step-by-step instructions, developers can create a secure application that protects their users' data from unauthorized access.