There are six main types of validation controls :-
It checks whether the control have any value. It's used when you want the control should
not be empty.
It checks if the value in validated control is in that specific range. Example
TxtCustomerCode should not be more than eight length.
It checks that the value in controls should match some specific value. Example Textbox
TxtPie should be equal to 3.14.
When we want the control value should match with a specific regular expression.
It is used to define UserDefined validation.
It displays summary of all current validation errors.
Note:- It's rare that some one will ask step by step all the validation controls. Rather they
will ask for what type of validation which validator will be used. Example in one of the
interviews i was asked how you display summary of all errors in the validation
control...just uttered one word Validation summary.