A common example of capillary action can be observed when you place a paper towel in a glass of water.
When one end of the paper towel touches the water's surface, the water molecules begin to move up into the paper towel. This happens because the adhesive forces between the water molecules and the fibers of the paper towel are stronger than the cohesive forces between the water molecules themselves. As a result, water is "pulled" up through the tiny spaces or pores within the paper towel, demonstrating capillary action.
You can see this effect clearly as the water spreads along the paper towel, illustrating how liquids can travel upward against gravity through narrow spaces. This phenomenon is also essential in various biological processes, such as the way water moves through the roots and stems of plants.