You'll find two very different things called MVC. One is a variety of designs that date back to the very beginnings of object oriented design and Smalltalk for "fat client" applications. The other is web oriented, typified by Struts and other "front controller" designs. They are so different I hesitate to call the stateless web designs MVC at all. As you Google and read, be careful to know which style you're studying. Scroll down to the OO, UML, etc. forum if you want to dig into the theory.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi