Types of validation controls provided by ASP.Net
There are following types of validation controls provided by ASP.Net:
1. Required Field Validator
2. Compare Validator
3. Regular Expression Validator
4. Range Validator
5. Custom Validator
These controls are server side controls. Though in up-level browsers that is IE 4.0 and above these can be enabled on client side also.
All these controls have a property known as Control To Validate. Needed Field Validator ensures data entry into the Control To Validate.