In a democracy, the rights of the majority can overwhelm the rights of the minority, whereas in a republic, a constitution or charter protects its citizens with laws that cannot be changed by a simple majority vote.
Both a democracy and a republic use representational forms of government. In a pure democracy, the majority vote decides the outcome of laws and initiatives. In a republic, the government is constrained by the limitations placed on it through a constitution or charter. The term democracy is often confused with the representative democracy used in the United States. The United States is a republic, and its elected officials are bound by the protections of the constitution. They vote "democratically" to create laws, but no matter how great the majority, they still must uphold constitutionally protected rights. Changing the constitution is difficult and can only be done through amendments to the constitution. To further protect against the threat of tyranny, the governmental powers are divided into separate branches. In direct democracies, there is no constitutional protection in place, and the majority vote can override any law. There are some states within the United States that do allow people to vote directly on policies through initiatives or referendums.