Keywords are judged by monthly search volume (how many people search) together with competition (how many posts and ads there are). A keyword with high volume is hard to rank for if competition is too strong, and a keyword with low volume can be very valuable if it is what customers search right before deciding.
Search volume is checked with tools such as the keyword tool in Naver Search Ads and Google Keyword Planner.
How MAKE Marketing uses it
In MAKE AI keyword research, MAKE Marketing chooses which keywords to target with an opportunity score that compares monthly search volume with recent publishing volume.