Renters insurance covers your belongings, not the building you live in. If a kitchen fire destroys your laptop and furniture, your policy helps pay to replace your belongings. When a burst pipe in the apartment above floods your bedroom and ruins your clothes, you're covered. But if that same pipe damages the hardwood floors or drywall, that's your landlord's responsibility.
Your renters insurance won't pay for structural repairs to the unit. Your landlord uses their property insurance for walls, floors and building fixtures. Understanding this difference helps you know what your policy actually protects.