How true density works and why it is important
In The Masterclass Webinar Michał described the True Density, I encourage you to watch it, the video below is set up to start right there, don't worry about the 2h the webinar duration.
True Density, is a kind of similar (we like to say improved) to TF-IDF. True Density gives you all the terms that your competitors are using commonly and t takes your content length into account as well. That means Surfer will provide suggestions that if followed, keeps the same density to your competitors no matter how long your content is.
For example, if your content is 5,000 word-long and your competitors have 2,500 words on average, Surfer will suggest using phrases twice as many times as your competitors.
Release note on True Density
Read the full story about where does this data come from, how it is calculated, and where to find it in Surfer. True Density Release Note