This is Market Profile script. "Market Profile is an intra-day charting technique (price vertical, time/activity horizontal) devised by J. Peter Steidlmayer. Steidlmayer was seeking a way to determine and to evaluate market value as it developed in the day time frame. The concept was to display price on a vertical axis against time on the horizontal, and the ensuing graphic generally is a bell shape--fatter at the middle prices, with activity trailing off and diminished at the extreme higher and lower prices." You better search it on the net for more information, you can find a lot of articles and books about the Market Profile.
You have option to see Value Area, All Channels or only POC line, you can set the colors as you wish.
Also you can choose the Higher Time Frame from the list or the script can choose the HTF for you automatically.
=> "Price in POC"
=> "Price went above POC"
=> "Price went below POC"
Array used for the lines instead of variables
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.