MVC - Model, view, controller

Model：指database o既model，data access
View ：表現出黎o既形式，data presentation，user interface
Controller: Business logic，data process，program o既behavior

一般web application裏面，view係由 html黎表現，
view 收到user input，就會叫controller做野，
controller跟據user input黎update個model
view再從model拎新o既數據