A trend line is a straight line that connects two or more price points on a chart, indicating the direction of price movement over time. Traders use trend lines to identify support or resistance levels, helping to visualize the market trend - whether it is upward (bullish), downward (bearish), or sideways (consolidation). Properly drawn trend lines can assist traders in making informed decisions about entry and exit points, as well as managing risk by providing a visual reference for potential reversal points.