Here's how it works:

* Buoyant Force: When an object is submerged in water, the water exerts an upward force on the object. This force is called the buoyant force.

* Density: The buoyant force is directly related to the density of the fluid (in this case, water).

* Displacement: The buoyant force is also equal to the weight of the water displaced by the object. This is known as Archimedes' Principle.

Here's a simple explanation:

1. Weight: Every object has a weight, which is the force of gravity pulling it downwards.

2. Displacement: When an object is placed in water, it pushes some of the water out of the way (displaces it).

3. Buoyant Force: The water that was displaced exerts an upward force on the object (the buoyant force).

4. Floating vs. Sinking: If the buoyant force is greater than or equal to the weight of the object, the object will float. If the weight is greater than the buoyant force, the object will sink.

In short: An object floats because the water pushes back on it with a force (buoyancy) that is equal to or greater than the force of gravity pulling it down.