An important aspect of creating ASP.NET Web pages for user input is to be able to check that the information users enter is valid. ASP.NET provides a set of validation controls that provide an easy-to-use but powerful way to check for errors and, if necessary, display messages to the user.
There are six types of validation controls in ASP.NET
RequiredFieldValidator (The RequiredFieldValidator control ensures that the required field is not empty).
RangeValidator (The RangeValidator control verifies that the input value falls within a predetermined range).
CompareValidator(The CompareValidator control compares a value in one control with a fixed value or a value in another control).
RegularExpressionValidator(he RegularExpressionValidator allows validating the input text by matching against a pattern of a regular expression).
CustomValidator(The CustomValidator control allows writing application specific custom validation routines for both the client side and the server side validation).
There are so many Jquery to validate your controls in client side.