The most commonly observed real life example of osmosis is the pruning of the fingers when they are immersed in water for a lengthy period of time. Other easily observable examples of osmosis include soaking dehydrated fruit and vegetables until they expand, or watching a freshly watered plant absorb water through the soil.
In very simple terms, osmosis is the movement of water across a selectively permeable membrane. The process is driven by a difference in solute concentrations on each side of the membrane. Osmosis occurs in almost all animals cells. Indeed, simply hydrating the body with a refreshing glass of water is a living example of the osmosis process.
The pruning of the extremities after a long bath or a swim is a good example of osmosis because many people assume that the fingers have wrinkled because they have lost water. In fact, fingers prune in water due to osmosis, as the external water around the body is more diluted than the water in the body. The external water essentially attempts to enter the body by attempting to cause equilibrium with it, and pruned fingers are a sign of water absorption as water attempts to enter the body. This also explains why dead animals rise to the surface in bodies of water, as the carcass soaks up water and becomes bloated over time.