Ozonolysis is a cleavage reaction by ozone. Cleavage is a reaction that completely break down the carbon carbon double bond and form two new products. The reagent of the cleaving of alkene is ozone. Ozone break down the pi bond of carbon carbon double bond and forms ozonide. That is called ozonolysis. After Ozonolysis the hydration of ozonide happened and forms aldehyde and ketone.
Ozonolysis means entrance of ozone. Ozonolysis of alkene is entrance of Ozone in alkene. Hydrolysis means adding of water with any chemical compounds. In chemistry every reaction containing the symbol sis means adding or ebtrancing.