I'm not quite sure but coke was a type of bitter medicine a long time ago. the inventor used coke when people were sick in very cold places. as he grew older, he sold coke to another guy. this new guy turned coke medicine into CocaCola.
the difference between coke and pepsi is that pepsi has less sugar. coke has this sourish taste that pepsi doesnt have . also if you drink cocacola it gives you this hurting thing in your chest but pepsi doesnt.