viewstate is just like hidden field.Basically all html
controls are stateless .if u want maintain state for page
level we can use viewstate.

view state that automatically preserves property values of 
the page and all the controls on it between round trips.

Actully All HTML controls are state-less ie;-these can not 
store any type of clients inputs.when ever we send the page 
to server it will send this page as fresh one.so we loose 
the data what we have entered.

To store all these data (temporarly) in clients browsers ,
.Net provide a concept that is known as View state .View 
state store the data in encoding format,so that one can not 
gues it easily.

view state is used to find the current state of an object,
forexample with the help of view state we can find that 
whether is a button is click or not;

ViewState is a built-in structure for automatically 
retaining values among multiple requests for the same page. 
The view state is internally maintained as a hidden field 
on the page but is hashed, providing greater security than 
developer-implemented hidden fields do.
Following are the benefits of using ViewState:- 
	No server resources are required because state is 
contained in a structure in the page code.
	Simplicity.
	States are retained automatically.
	The values in view state are hashed, compressed, 
and encoded, thus representing a higher state of security 
than hidden fields.
	ViewState is good for caching data in Web farm 
configurations because the data is cached on the client. 
Following are limitation of using ViewState:- 
	Page loading and posting performance decreases when 
large values are stored because 
	View state is stored in the page.
	Although view state stores data in a hashed format, 
it can still be tampered with because it is stored in a 
hidden field on the page. The information in the hidden 
field can also be seen if the page output source is viewed 
directly, creating a potential security risk. 
	If page get destroyed or refresh information which 
is stored in view state gets vanished.

Below is sample of storing values in view state. 
this.ViewState["EnterTime"] = DateTime.Now.ToString();

While excuting the page, it will go under the fallowing 
steps(or fires the events) which collectivly known as Page 
Life cycle.
Page_Init -- Page Initialization
LoadViewState -- View State Loading
LoadPostData -- Postback data processing
Page_Load -- Page Loading
RaisePostDataChangedEvent -- PostBack Change Notification
RaisePostBackEvent -- PostBack Event Handling
Page_PreRender -- Page Pre Rendering Phase
SaveViewState -- View State Saving
Page_Render -- Page Rendering 
Page_UnLoad -- Page Unloading

sorry, kavitha answer is wrong. There is no textchange when 
loading a page

Init
loading
TextboxTextchanged
buttonclic
pageunload
pagedispose


The page is intialize the events,after that the page is 
loading,after that controls is rised after page unloading 
and pagedispose is removing the unnecessary objects

init
load 
prerender
unload

Page_Init()-when page is first inistiated.
Page_Load()-when page is first loaded to server
Page_PreRender()-Few moment befor while html code is viewed 
to user.
Page_unload()-Page is unloaded from server memory

Master page provides common structure and interface element 
for your web site. MasterPage act as a template and merging 
container for pages .
User Control just like other control, you can use it 
anywhere on your page and as many as you want.

in master page u can't perform caching as well as u can't
apply theme.
but in user control u can apply theme also u can perform
caching on user control.

Early binding::  Properties and method can be identified by 
compile time.
Example:  dim rs as recordset

Late binnding: Properties and method can be identified by  
Run time.
Example:  dim  obj as classname
                 set obj=new  classname

Early binding means one of function or type declaration 
compile first then it excute.
late binding function or type direct excute at runtime

Dynamic query will build at runtime where static query is
already builded.