Change in Supply (Assuming No Change In Supply)

Shift in supply curve to the right creates excess supply at the point E. This puts pressure on prices to falls from OP to OP1 and quantity rises to OQ1. New equilibrium is set at point E1. At the new equilibrium there is no tendency for output or price to change.
vLeftward shift in supply curve leads to excess demand at the initial equilibrium E. This exerts an upward pressure on the prices leading to rise in equilibrium price to OP2 and quantity to OQ2. New equilibrium is attained at point E2.