Difference Between Instanced Static Mesh and Merging Actors

I currently trying to figure out whats is the best way to optimize static meshes.

Wondering whats the difference and what either would be used for.

Instanced static mesh allows you to reduce memory and draw calls and still manage each object individually. So it gives you the performance improvement while still allowing you more control.

Nice, but do you know what Merging Actors do? and why I would use it over Instanced Static Mesh?

It’s much easier to merge objects but it uses more memory and then can only use one lightmap. Really the only advantage is that it’s easier to just merge objects.