Screen tearing occurs when a display shows information from multiple frames in a single screen draw. This happens when the graphics card's frame rate is out of sync with the monitor's refresh rate, leading to a disjointed image. As a result, parts of different frames are displayed simultaneously, creating a torn effect. This issue is commonly seen in fast-paced video games or during high-motion video playback. Technologies like V-Sync and G-Sync are designed to reduce screen tearing by synchronizing the frame rate of the graphics card with the refresh rate of the monitor, providing a smoother visual experience.