A parallel channel can be formed when the price of a security is restricted by supply and demand and can be upward, downward or sideways trending. It shows the trend on which the security might be headed towards or on the verge of breaking it to reverse its direction. It can occur on various time frames and can be created on various instruments like stock, mutual funds, ETFs etc.
The two parallel lines act just like the Resistance and Support. The upper line acts like the Resistance and the lower line acts like Support. A lower trendline is when the price pivots higher, and an upper trendline when the price pivots lower. The steepness of the parallel lines decides the direction of the price it moves.
Ascending channel will be bounded by positive lines indicating that the price is trending higher with each closing of the bar. Likewise, a breakdown of the lower line means that price has moved significantly and now it will see some profit booking and makes a good opportunity for profit booking.
Descending channel indicates that price is trending lower with each bar it is forming. Whereas a breakout of the upper channel conveys that the trend has changed and now the price will move upwards.
As in this example of Axis Bank Daily chart, you could see a Descending Parallel channel which did retrace to its lower price channel and that makes it a good entry point after which it broke the upper channel with good volume confirming its upwards rally.