That particular image is probably achieved using different kinds of maps
A diffuse map that tells where the color is: in the puddle you can have the same color as the ground or any other color to get the water a tinting effect in cases the reflecting isn’t 100%
A normal map or bump map that creates that 3d effect on the ground: in the puddle water the little rock in the middle as normals pointing in various directions but in the water parts the normal is always point up to make the water plain and the rock sticking out
A reflection map to tells where reflection exists and how strong: this is a black and white map where black means no reflection and white means full reflection and any gray color in between means it’s translucent, in the image the puddle has full reflection, but along the edges it’s starts to blurs out, notice though that the ground has some reflections here and there to make it look wet
A specular map for different reasons: this one is optional and i don’t think that particular image has it because the reflection map usually replaces the specular map, but sometimes this map is used for additional effects like blurring out the reflection or make it shiny (think sweat on a body), i’m not entirely sure on those red and greens lights on the floor being specular maps or not
the reflection is either produced in-engine with a bunch of complicated tricks or you can use cubemaps that mimic and fake a reflection. I would go for the cubemaps
