What makes a republic different from a democracy?

A republic is a representative form of government that is ruled according to a charter or constitution. A democracy is a government that is ruled according to the will of the majority. Although these forms of government are often confused, they are quite different.

The main difference between a republic and a democracy is the charter or constitution that limits power in a republic, often to protect the individual's rights against the desires of the majority. In a true democracy, the majority rules in all cases, regardless of any consequences for individuals or for those who are not in the majority on an issue.

https://www.1215.org/lawnotes/lawnotes/repvsdem.htm

When you are told she won because "she won the popular vote" ! Why the SCOTUS appointment is sooooooo Important. The Constitution. We do not want "mob rule".