A buckling-restrained braced frame is like a big skeleton for a building that wants to stay standing even if there's a lot of shaking or moving around.
Imagine if you were playing with a bunch of toy building blocks and you stacked them up really high to make a tower. But then you started shaking the table or the floor, and the tower started wobbling from side to side, and you were afraid it might fall down.
Now imagine if you had some really strong straws to put between the blocks in your tower. Those straws would help hold the blocks together and keep them from falling over, even if the whole table was shaking.
That's kind of like what a buckling-restrained braced frame does for a real building. It's made up of special parts that are designed to be really strong and stiff, like the straws in your tower.
These parts are placed in strategic spots throughout the building, like along the walls or inside the columns. When the building starts to move, like during an earthquake, these bracing pieces help transfer the forces so that the building stays stable and doesn't collapse.
So even if the building is shaking a lot, the buckling-restrained braced frame helps keep everything together and prevent it from falling down.