what is agile model in mvc ?

Let me clear few things. 

 

Agile / Waterfall is the Software Development methodology. It has nothing to do with your technology. 

 

If you have requirement changes frequently, we prefer Agile methodology. In agile we have sprints. We  have user story and Product Backlog. Based on the capacity and priority we take up User Story. User story are the bunch of requirements which are pending or ideas to implement. In agile there will be Scrum master / Product Owner. There will be no project manager in Agile.

 

There are different flavours of Agile:

1) Scrum

2) Kanban 

 

You can read more  

http://www.tutorialspoint.com/sdlc/sdlc_agile_model.htm

http://kanbanblog.com/explained/