Why does the render look like this?

[utiq]

Please check the screenshot attached, why does the viewport look like that? it also looks the same when I render

[frankmci]

Looks like your Ray Epsilon value in the Kernel settings is not in tune with the scale of your scene. (Epsilon is usually used as the variable representing the degree of precision.) Try shifting the decimal point a digit or two to the right. Since that value controls how precisely a ray intersects with a surface, in larger scenes, you don't want to push the rays too close to the surface. If the the rays are calculated with less precision than the scale of the scene can handle, it causes floating point rounding errors start show up. Essentially, the surfaces are casting shadows on themselves.

[elsksa]

In complement to what @frankmci said,
majority of cases result in an inappropriate scene-scale, which will cause other problems down the line.

I emphasize on recommending to favor proper scene-scaling than considering changing the Ray Epsilon as a workaround / dirty-solution.

[utiq]

Thanks! it was that!