A tackk by @stony_camacho & @SageHeishman
Equilibrium is a condition or state in which economic forces are balanced. These economic variables will be unchanged from their equilibrium values in the absence of external influences. Economic equilibrium may also be defined as the point where supply equals demand for a product – the equilibrium price is where the hypothetical supply and demand curves intersect.
In this graph, the equilibrium is at 60 and 500. At a price higher than equilibrium, demand will be less than 500, but supply will be more than 500 and there will be an excess of supply in the short run.