This number refers to the vertical resolution of the image, measured in lines of pixels.
: Cultural barriers, the isolation of living abroad, and the realization that love alone isn't always enough to bridge two different worlds. Technical Specifications Explained
Based on the naming pattern you’re using ( What.Comes.After.Love.S01E03.x265.720p.friDay.W... ), here’s a draft piece suitable for a release description, NFO file, or subtitles blog. I’ve kept it neutral and informative.
Here is a draft of an informative blog post explaining the technology behind the filename.