The Electoral College made easy:
Rather than the people of California and New York (highest populations) running the whole country, the people of each state has an equal vote, including New Hampshire, Wyoming, Rhode Island, the Dakotas, Iowa, etc.
The difference between a Democracy and a Republic:
Democracy, i.e., the popular vote, is mob rule. Great if you're part of the mob but horrible if you aren't.
Republic, form of government that is not ruled by a monarch but by a central leader (such as a president) and the representatives elected by the people, a government of the people. What's important to remember is that a Republic is supposed to ensure the people in Iowa have as much power as people in New York.
Stop calling the United States of America a democracy. It isn't. It's a Republic.