Question

What is surface tension?Explain.

Answer 1

Surface tension in the force that holds fluids(more specifically liquids) together.
Surface tension is the reason why liquids form droplets.
Surface tension is the reason why you can see the surface of a liquid the way it looks at the first place.

Answer 2

The liquid molecules which are below the surface are in equilibrium.  The liquid molecules which are at the surface are attracted by other molecules in downward direction. So, a force is originated to balance the surface molecules which is equal but opposite in direction to the downward force. This force is called surface tension.