By definition, a republic is a representative form of government that is ruled according to a charter, or constitution, and 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.
Adding to the confusion over the difference between the two forms of government is the fact that, in practice, there are many variations of each. For example, a representative democracy is one in which, like a republic, officials are elected to vote on behalf of the people on most issues, rather than having all of the citizens vote on every issue. Furthermore, a constitutional democracy is a representative democracy in which the government's power is restricted by a constitution. In essence, this is a republic, so for practical purposes, the difference between a republic and a constitutional democracy is often largely one of semantics.
Government by the People
In both types of government, decisions are made by the people or their representatives rather than by a monarch. The head of state, in most cases, is referred to as a president and is elected by the people, directly or indirectly. Government representatives in either type of government also are elected by the people. In a direct democracy, in which people themselves vote on all issues, government officials or representatives merely carry out the will of the majority rather than voting on behalf of the people.
Protecting Individuals' Rights
A true democracy is rare because of the potential for it to turn into what might be called "mob rule." This occurs when the majority makes decisions that benefit itself at the expense of the minority. For example, a racial, religious or socioeconomic class that consists of more than 50% of the voting population could — theoretically — vote to give itself certain benefits or to oppress or restrict those in the minority. In a true democracy, there is no legal power that protects minorities.
In a republic or a constitutional democracy, however, the charter or constitution typically guarantees certain rights to individuals or minority groups. This prevents those rights from being taken away or infringed upon by the will of the majority. This protection is fundamental for the republican form of government.