tearing
also: screen tearing, display tearing
A visual artifact that occurs when a display buffer is updated while the monitor is actively refreshing, causing different parts of the screen to show content from different frames.
Tearing happens when the graphics system writes a new frame to the display buffer while the monitor's electron beam is reading from it to paint the screen. This causes horizontal lines or bands where the top portion displays one frame and the bottom shows another.
For example, in a fast-moving game, you might see the upper half of a character from one frame position and the lower half from the next frame position, creating a jagged "torn" appearance along the screen.
Modern systems prevent tearing using vertical sync (VSync), which synchronizes frame updates to the monitor's refresh rate, or adaptive sync technologies like FreeSync and G-Sync that adjust refresh rates dynamically. This is particularly important on high-refresh displays and gaming setups.