This ASP.NET reference explains Validation control class properties and its descriptions.
The validation controls are found in the System.Web.UI.WebControls namespace and inherit from the BaseValidator class. This class defines the basic functionality for a validation control. The next table describes its key properties:
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in System.Web.dll)
Property
Description
Supported in .NET version
ControlToValidate
The property is used to [...]