Serpstat doesn't collect groups according to the most high-frequency keywords. Instead, we study all the keywords due to their intersections in the SERP.
Serpstat checks the connection strength between all clustered keywords, depending on the settings that you specify. There are two types of strength: Weak and Strong, and two types of clustering: Soft and Hard.
Keywords are combined into groups (clusters), clusters are combined into groups of a higher level (superclusters), and superclusters are combined into groups of an even higher level (protoclusters)
After clustering is completed, you can perform text analytics on the content of your site based on text analysis on competitors' sites.