How to explain the density layer legend

[_CD_]

Hello world !

I made a map with a density layer. It displayed my point (Shop, for example) with a 25km influence radius (no ponderation or something else).

In this "zoomed" example with only 3 points, the legends tells us that the maximum density is 1.88.

My question is :

How this 1.88 value is calculated ?

I can't find the right explanation sentence. Something like : "At this location, there's 1.88 shop" ?

Thx for your help !