Zend MVC Structure

• Model - This is the part of your application that defines its basic functionality behind a set of abstractions. Data access routines and some business logic can be defined in the model.
• View - Views define exactly what is presented to the user. Usually controllers pass data to each view to render in some format. Views will often collect data from the user, as well. This is where you're likely to find HTML markup in your MVC applications.
• Controller - Controllers bind the whole pattern together. They manipulate models, decide which view to display based on the user's request and other factors, pass along the data that each view will need, or hand off control to another controller entirely. 
  
  
  This post is taken from http://framework.zend.com/manual/1.12/en/learning.quickstart.intro.html. More info you can get from it.