「validator」を英語から日本語に翻訳する

A server control, included with ASP.NET, that verifies user input. The input is checked as it comes from HTML server controls and Web server controls (for example, a Web page form) against programmer-defined requirements. Validation controls perform input checking in server code. If the user is working with a browser that supports DHTML, the validation controls can also perform validation using client script.