Differences between asp.net 1.1 and asp.net 2.0

Asp.net 2.0 many new features like

* Partial Classes
* Master pages
* Skins and Themes
* Roles and MemberProfiles
* Generics
* Added many new server contols like GridView,DetilsView,FileUpload etc..,
* Web Personalization - Web Parts
* New Folders lime App_Browsers,App_Code,etc..,

View State and Cookies

viewstate 

The ViewState property provides a dictionary object for retaining values between multiple requests for the same page. This is the default method that the page uses to preserve page and control property values between round trips.

When the page is processed, the current state of the page and controls is hashed into a string and saved in the page as a hidden field, or multiple hidden fields if the amount of data stored in the ViewState property exceeds the specified value in the MaxPageStateFieldLength property. When the page is posted back to the server, the page parses the view-state string at page initialization and restores property information in the page.

You can store values in view state as well. For more information on using View State, see ASP.NET View State Overview. For recommendations about when you should use view state, seeASP.NET State Management Recommendations.

Cookies

<div class="subsection" xmlns="http://www.w3.org/1999/xhtml">

A cookie is a small amount of data that is stored either in a text file on the client file system or in-memory in the client browser session. It contains site-specific information that the server sends to the client along with page output. Cookies can be temporary (with specific expiration times and dates) or persistent.

You can use cookies to store information about a particular client, session, or application. The cookies are saved on the client device, and when the browser requests a page, the client sends the information in the cookie along with the request information. The server can read the cookie and extract its value. A typical use is to store a token (perhaps encrypted) indicating that the user has already been authenticated in your application.

For more information about using cookies, see Cookies and ASP.NET State Management Recommendations.

What is are the difference between them?

A great article : How to Choose From Viewstate, Session, Application, Cache, and Cookies

Some good discussion about the difference between Session and Viewstate : Session Vs ViewState

Why we to go for MVC

There are various positive points to moving towards MVC

1.  TDD support out of the box as most of the design is based on interfaces.
2.  SEO friendly URL by design (though now this is possible in ASP.NET 4 as well)
3.  No ViewState (this may seem a bit of moving backward to some), but overall a good design decision.
4.  Clean View Markup (no additional HTML emitted)
5.  100% extensible.  You can add your own controller with IOC, switch view engines at will, control model binding at wish etc.
6.   Rich UI support (possible through client side JS libraries like jQuery UI and others).  Telerik has released some controls for MVC which includes Grid control as well (which are merely HTMLHelpers)
7.  Session, JS, Ajax works.  Validation is even more powerful with DataAnnotations and jquery.
8.  Is MVC faster?  Yes by default because of lack of viewstate and clean markup.  But performance is subject and MVC by design is more performant that traditional ASP.NET webforms (though webforms can be made as fast as required.
9.  Out of the box support for mitigating antiforgery attacks and XSS vulnerability (though asp.net does has this to some extent)
10.  Out of the box minimal IOC support.
11.  Full control over rendered HTML
12.  Pluggable architecture
13.   And much more....

Couple of limitations (though not exactly)
1.  Learning curve as most asp.net developers are used to windows form model for web development.


NOTE:  Webforms is not bad.  But by design it encourages many bad practices.  A webform at the hands of careful developer is as or could be even more productive than MVC.  Just my thought.

Additional readings at http://msdn.microsoft.com/en-us/magazine/dd942833.aspx

http://www.slideshare.net/JesseAnderson/mvc-5697864 

http://www.davidferguson.me.uk/Blogs/Post/why-use-mvc-over-web-forms

Thanks...