In the context of technical analysis, a trend line is a straight line that is used to connect two or more price points and is used to identify a current trend in the market. The trend line is used to define whether a particular market is in an uptrend (price is increasing), a downtrend (price is decreasing), or is moving sideways (price is consolidating).
Trend lines are often used in conjunction with other technical indicators, such as moving averages, to provide a clearer picture of the current trend and potential future market movements. A trend line can be either upward sloping, downward sloping or horizontal. Typically, a break above/below a trendline is considered as a signal of trend reversal.