A building isn't one thing resisting forces — it's a chain of specific elements each doing a specific job. Click any part of the frame to see what it resists and why it matters.
Buildings resist force through two systems: gravity systems carry vertical loads down, and lateral systems resist horizontal forces like wind and earthquakes.
The gravity system carries the weight of the building and everything in it straight down to the ground. It's the beams, girders, columns, and slabs that make up the floor framing. Design is driven by span length (longer span = deeper beam), load magnitude (heavier floors need bigger members), and deflection limits. Most of a building's structural steel or concrete goes into the gravity system.
The lateral system resists sideways forces — wind pushing on walls and earthquakes shaking the foundation. Three main types: shear walls (concrete or masonry walls that act as vertical cantilevers), braced frames (diagonal steel members forming triangles), and moment frames (rigid beam-column joints that resist racking through bending). Each has tradeoffs in stiffness, ductility, cost, and architectural impact.