ASP.NET is Microsoft’s big leap after Active Server Pages (ASP), ASP.NET provides flexible and unified web development model to build robust, scalable and the enterprise class web applications.ASP.NET supports Web Forms and Model – view – Controller (MVC).

ASP.NET Web Forms
ASP.NET Web Forms provides look and feel of web applications through UI elements, similar to the windows forms i.e. methods, properties, events and controls within them. Web Forms creates higher level abstraction for developers. UI elements of Web Forms have ability to render in various requests for markup languages.
Advantages of ASP.NET Web Forms
Rich Server Controls Encapsulate flexible Rendering:- If want to develop HTML, CSS and JavaScript based web application without having cross –browser compatibility issues then Web Forms can deploy the same without any hassles, as it detects and renders application according to various browsers.
Event Driven and Stateful Programming:- As the cliché ‘HTTP is a stateless protocol’. ASP.NET Web Forms facilitate stateful programming through ViewState, Postbacks, code behind and event driven programming. Web Forms empower developers to double click on control (i.e. button) and they can generate bunch of code for handling user’s clicking to the server side with user defined logic inside.
Productivity and Rapid Application Development:- Increases productivity for small teams, as less complex application development and requires less code. Developers can achieve rapid application development without background complexities through various components like rich server controls, ViewState, code behind and event driven paradigm.
While ASP.NET Web Forms offer many advantages, there are some disadvantagesas well.
ASP.NET MVC
Model – View – Controller (MVC) is the architecture to combine input logic, business logic and UI logic with Separation of Concerns (SoC). Many known issues of Web Forms can be fixed with ASP.NET MVC and has more advantages, for example control size or disable ViewState. ASP.NET MVC is the next level web application framework based on MVC architecture with the main reasons like testability and Separation of Concerns (SoC) to achieve loosely coupled modules with in an application.ASP.NET MVC is the part of ASP.NET framework, so previous skills from ASP.NET and ASP.NET Web Forms can easily be applied to develop ASP.NET MVC based applications.
Advantages of ASP.NET MVC
Separation of Concerns (SoC) with Enhanced Performance:- ASP.NET MVC provides Separation of Concerns (SoC) that means your project remains less complex. No automatic state control management and don’t support ViewState. No ViewState support means more enhanced performance by reduced page size.
Routing with REST and SEO Friendly:- Provides ad hoc HTTP modules that can rewrite URLs with RESTful interface, if you think one step ahead new ASP.NET 4.0 with JavaScript frameworks empower developers to achieve better control over ID elements. AJAX with postback can produce user friendly and SEO friendly pages through the history management APIs of ASP.NET 3.5 SP1.
Web stateless behaviour with full control over HTML:- No server controls means time to use HTML input controls and complete CSS and script freedom. We can manage each ‘ID’ separately and HTML rendering occurs by separate engine, so we don’t have to rely on ASPX physical server files.
Reusable Components and Test driven Deployment:- Controllers don’t depend upon any specific view. This is the reason you can achieve components reusability with ASP.NET MVC, as you can use them for multiple views. Controller is the separate class in ASP.NET MVC, so you can create and perform unit tests simultaneously for methods in an application.
Concurrent Development with Extensibility:- ASP.NET MVC based applications provide concurrent development. Application development relies on loosely coupled layers, so your team can work simultaneously on Model, Views and Controller. Multiple view engines like razor, aspx or custom engine are flexibly supported by ASP.NET MVC.
While ASP.NET MVC offers many advantages, there are some negligible disadvantages as well.