What does "most relevant reviews" actually refer to in discover?

Reading reviews on discover gives you 3 sorting options, “most relevant”, “most recent” and “highest ratings”.

Most recent & highest ratings are self explanatory, one shows the 5* reviews, then the 4* reviews, the 3*, the 2* and lastly the 1* reviews. The other shows newest reviews first, oldest reviews last.

But what exactly does “most relevant” mean in this context? When sorting by most relevant, what determines the order of the reviews? I’m not sure that I understand who or what these reviews are supposed to be relevant to.

FYI: I’m using KDE Linux.

“Most relevant” orders the reviews by the ratio of “helpful” votes to “unhelpful” votes.