So there is always a lot of talk about the difference between these two systems of government, and often times some more polarizing conversation as to whether the United States is one or the other. Here's what they both entail:
Democracy : The United States is the worlds "Democratic" beacon. It means "The people's system." The power lays with the people, who can vote and essentially have control over the democratic process. Because the sovereignty lies with the people, minorities can be crushed from above by majorities, leaving a platform for mobocracy (it is like it sounds).
Republic : This form of government is in fact what the United States actually practices. It is one where the people elect representatives who then establish a central leader (president) to represent everyones best interests (pretty streamlined and can bring these leaders dangerously far from the issues the people are faced with). All of these factors come together to create "law," which is the basis of power.
Despite everything you've learned about our "democracy," a little bit of due diligence makes it clear we are actually a republic (which is a good thing, so we can protect the minorities). When you understand this, it's clear to see how it would've been possible for such polarizing political parties to form. But, that is a conversation for another day...
Everyone have a great day :)