A republic is a form of government in which the people, or some significant portion of them, retain supreme control over the government. The term is generally also understood to describe a government where most decisions are made with reference to established laws, rather than the discretion of a head of state, and therefore monarchy is today generally considered to be incompatible with being a republic. One common modern definition of a republic is a government having a head of state who is not a monarch. The word "republic" is derived from the Latin phrase res publica, which can be translated as "a public affair", and often used to describe a state using this form of government. - Source: Wikipedia
