Explore the importance of ground in differential pair signals for PCB layout and board design in this comprehensive 42-minute video featuring expert insights from Eric Bogatin. Delve into topics such as real differential pairs versus single-ended lines, transformer-coupled pairs, cable versus PCB routing, common mode versus differential mode, and the impact of return planes. Learn through simulations and examples comparing single-ended and differential signals in various scenarios, including cables and PCBs without ground planes. Gain valuable knowledge on tightly versus loosely coupled differential pairs, impedance considerations, and practical applications to enhance your high-speed digital design skills.