We can not give one or two difference , there are so many like : structure of project in mvc completely changes compare to web form and performance related upgradation

Webform are event based & MVC is eventless

Asp.Net Web Forms: 1. Asp.Net Web Form follow a traditional event driven development model. 2.Asp.Net Web Form has server controls. 3.Asp.Net Web Form supports view state for state management at client side. 4.Asp.Net Web Form has file-based URLs means file name exist in the URLs must have its physically existence. 5.Asp.Net Web Form follows Web Forms Syntax 6.In Asp.Net Web Form, Web Forms(ASPX) i.e. views are tightly coupled to Code behind(ASPX.CS) i.e. logic. 7.Asp.Net Web Form has Master Pages for consistent look and feels. 8.Asp.Net Web Form has User Controls for code re-usability. 9.Asp.Net Web Form has built-in data controls and best for rapid development with powerful data access. 10.Asp.Net Web Form is not Open Source.Asp.Net MVC: 1.Asp.Net MVC is a lightweight and follow MVC (Model, View, Controller) pattern based development model. 2.Asp.Net MVC has html helpers. 3.Asp.Net MVC does not support view state. 4.Asp.Net MVC has route-based URLs means URLs are divided into controllers and actions and moreover it is based on controller not on physical file. 5.Asp.Net MVC follow customizable syntax (Razor as default) 6.In Asp.Net MVC, Views and logic are kept separately. 7.Asp.Net MVC has Layouts for consistent look and feels. 8.Asp.Net MVC has Partial Views for code re-usability. 9.Asp.Net MVC is lightweight, provide full control over markup and support many features that allow fast & agile development. Hence it is best for developing interactive web application with latest web standards. 10.Asp.Net Web MVC is an Open Source.