Static mesh vs stationaty and movable?

I’m a beginner on unreal and i would like to understand the difference between those 3 modes (static, statio and move).
When I build my lights, the static mode gives me a really ugly result. Is what the problem is because my lightmap size is too small ?
thank you

maybe this will help Actor Mobility in Unreal Engine | Unreal Engine 5.0 Documentation