A Renko chart is built from price movement, not time. A new brick is only added once price moves a predefined amount (its “box size”) in either direction - unlike a candlestick chart, which always adds a new candle once a fixed time interval passes, regardless of how much (or little) price actually moved. This makes Renko charts useful for filtering out minor, low-significance price wiggles and focusing purely on meaningful directional movement.
Related Reading
See how Renko bricks are built and compared with area charts in Renko Charts and Area Charts Explained.