Introduction to static batching

Static batching is a draw call optimization method that combines meshes that use the same material, so that Unity can render them using fewer updates to the render state. Static batching can improve performance, memory efficiency, and reduce CPU overhead, leading to a smoother frame rate and better player experience.

Static batching combines multiple static meshes into one vertex buffer and one index buffer, using coordinates in world space. Each buffer can contain up to 64,000 vertices, but Unity can create multiple batches.

Static batching has the following limitations:

• Static batching supports only Mesh RenderersA mesh component that takes the geometry from the Mesh Filter and renders it at the position defined by the object’s Transform component. More info
  See in Glossary. Static batching doesn’t support Skinned Mesh Renderers.
• Static batching of transparent GameObjects might be limited because Unity sorts all meshes back-to-front before batching.

You can also manually combine meshes, but as a result you can’t cull meshes individually.

Additional resources

• Choose a draw call optimization method