Question

Explain Vapor Pressure ?

Answer 1

Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system. All liquids have a tendency to evaporate, and some solids can sublimate into a gaseous form. Vice versa, all gases have a tendency to condense back to their liquid form, or deposit back to solid form, as long as the temperature is below their critical temperature or decomposition temperature.

Answer 2

The ocean for example; has energy fluctuations, a small number of H2O particles are picking up energy and bursting into gas phase, just as some water vapor is condensing and landing in the ocean.
These particles pushing up are contribution to the vapor pressure