Here's why:

* Buoyant force is the upward force exerted by a fluid (like water or air) on an object immersed in it.

* Weight is the force of gravity acting on an object's mass.

Archimedes' Principle explains this:

* An object submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object.

When an object floats:

* The buoyant force is strong enough to counteract the object's weight.

* This means the weight of the fluid displaced by the object is equal to the weight of the object itself.

Example:

Imagine a wooden block floating in water. The block displaces a certain amount of water, and the weight of that water is equal to the weight of the wooden block. This is why the block floats.