Spring MVC and Spring Boot are exist for the different purpose. So, it is not wise to compare each other as the contenders.
What is Spring Boot?
Spring Boot is a framework for packaging the spring application with sensible defaults. What does this mean?. You are developing a web application using Spring MVC, Spring Data, Hibernate and Tomcat. How do you package and deploy this application to your web server. As of now, we have to manually write the configurations, XML files, etc. for deploying to web server.
Spring Boot does that for you with Zero XML configuration in your project. Believe me, you don't need deployment descriptor, web server, etc. Spring Boot is magical framework that bundles all the dependencies for you. Finally your web application will be a standalone JAR file with embeded servers.
If you are still confused how this works, please read about microservice framework development using spring boot.
What is Spring MVC?
It is a traditional web application framework that helps you to build web applications. It is similar to Struts framework.
A Spring MVC is a Java framework which is used to build web applications. It follows the Model-View-Controller design pattern. It implements all the basic features of a core spring framework like Inversion of Control, Dependency Injection.
A Spring MVC provides an elegant solution to use MVC in spring framework by the help of DispatcherServlet. Here, DispatcherServlet is a class that receives the incoming request and maps it to the right resource such as controllers, models, and views.
I hope this helps you to understand the difference.