What is a double check in chess?

Chess Tactics: Complete Guide - TheChessWorld

Forcing the King to run with the Double Check, Chess Tactics

Double-Check

How To Think During A Chess Game - Next Level Chess By GM Noël Studer

In this position, black chose to ignore the double check and

Chess Tactics for Intermediate Players –

The game Reti vs. Tartakower 1910 has one of the most powerful double checks ever! Have you ever used a double check to win a game of chess?, By ChessKid.com

Double Check - Learn to Play Chess, Chess Lessons for Beginners

Double Check - Learn to Play Chess

In order to win you should always double check chess design Photographic Print by tobistees