A gist on Supply and Demand's market force.

• Each of the buyers and sellers in a competitive market is little or not influenced on the market price.
• To analyze competitive markets, economists use the model of demand and supply.
• Determinants of demand include buyer's taste, income, expectation, price of substitute and complement.
• Supply totally depends on input prices, technology and expectations.
• In a demand and supply graph if both the curves intersect, it represents the market equilibrium.
• At the point of equilibrium, quantity demanded equals quantity supplied. 
• When the market price is above equilibrium, price falls.
• When the market price is below equilibrium, price rises.
• Three things how we need to analyze the supply demand diagram during an event on a market:

1.  See whether due to the event, which of the curve is shifted.
2. See the direction of the shift
3. Compare the new equilibrium to the initial one.