Validation control in asp.net?

can anyone deifne or give shirt note or own words on what validation control is in asp.net


plz no links.Validation control in asp.net?
As the term ';validation'; implies, it validates information.





Examples:


1) You have a textbox where someone should enter information (required)


- then you would use a required field validator


- unless an entry is provided, a FORM can't be submitted/can't continue





2) if the textbox in the above requires an entry **and** must be a valid email address


- in addition to the required field validator, you would add a regular expression validator


- so now, the textbox must contain something, and that something must be a valid email address (not just some text)





Validation control are therefore used when you need to collect information, and you want to ensure that the information you collect is validated as the right type of information.Validation control in asp.net?
A validation control is one that verifies the information entered into the control is in a specific format. Validation controls ensure that the form requesting the information from the user is input in a matter that the control can digest.