https://docs.unity3d.com/Manual/GPUInstancing.html
Use GPU Instancing to draw (or render) multiple copies of the same Mesh at once, using a small number of draw calls. It is useful for drawing objects such as buildings, trees and grass, or other things that appear repeatedly in a Scene .
GPU Instancing only renders identical Meshes with each draw call, but each instance can have different parameters (for example, color or scale) to add variation and reduce the appearance of repetition.