Trend lines are drawn on charts to help predict the general direction of price.It also help to determine good entry and exit point.they also help to see the reversals.
trendline always helps me to look at the trend in the market. in analyzing the market, I always make the first trendline, so I know the direction of price movement well.
so I think trendline is a line that is very helpful, especially for traders to follow the trend strategies. they must make the trendline make it easier to see the direction of the market.