Democracy

Derived from Greek, with dēmos meaning "the people" and -kratiā meaning "rule." Also referred to as direct democracy or pure democracy.

Republic

Derived from Latin, with rēs meaning "thing" and pūblicus meaning "of the people" or "of the public." The Republic is a system where the people create a small body or several small bodies to make the rules for society. Republics may also be referred to as representative democracy or constitutional government.

Democracy vs. Republic

A democracy is a form of government in which the people directly determine the rules. In contrast, a republic is a system where the people elect a smaller group of representatives to create the rules on their behalf.

In regards to the Electoral College, the small group of representatives would be electors and these electors would choose the president on behalf of the people.