HLC Bar Chart visually presents the data series as a sequence of bars only showing the High, Low, and Close (unlike OHLC bars that also show the Open). In cTrader charts HLC Bars show the price bars in either green or red, depending on the bar's close price relates to the previous close. When the close is greater than the previous close, then the bar is green; when the close is less than the previous close, the bar is red. A short horizontal bar drawn perpendicular to the High Low shows where the stock closed.
HLC was primarily the first step away from a simple Line Chart toward having more data to analyze. Since the closing price is regarded as the most important price, Bar Charts started out only showing the Close. By including the closing price using a horizontal bar, this helps people to see the line chart within the bar chart.
We can literally draw a line connecting each of the closing horizontal bars and we would see the Line Chart. What the HLC also provides is how much the stock moved up and down during the day. The Bar Chart is superior to the line chart for shorter term stock analysis. What the Bar Chart can tell us that the Line Chart does not is how much the stock price moved that day. How much a stock moves tells us how much momentum or buying or selling pressure is occurring during that day. If the bar is very short, then the price didn’t move much and this tells us that neither buyers or sellers were pushing price up or down. Neither were in control of the price. So there was a balance between the buyers and sellers. Balance of power doesn’t last for long however.