As define by Wikipedia - "Revenge is a harmful action against a person or group in response to a grievance, be it real or perceived. It is also called payback, retribution, retaliation or vengeance; it may be characterized as a form of justice, an altruistic action which enforces societal or moral justice aside from the legal system. Francis Bacon described it as a kind of "wild justice."
Also on the WIKI page -
ProverbsThe popular expression "revenge is a dish best served cold" suggests that revenge is more satisfying as a considered response enacted when unexpected or long feared, inverting traditional civilized revulsion toward 'cold-blooded' violence. In early literature it is used, usually, to persuade another to forestall vengeance long enough for wisdom to reassert itself. This sense is lost in recent presentations.
The idea's origin is obscure. The French diplomat Talleyrand (1754–1838) has been credited with the saying La vengeance est un mets que l'on doit manger froid. [Revenge is a dish that should be eaten cold.]. It has been in the English language since at least 1846, via a translation from the French novel Mathilde by Joseph Marie Eugène Sue: la vengeance se mange très-bien froide [sic], there italicized as if quoting a proverbial saying, and translated revenge is very good eaten cold. It has been wrongly credited[where?] to the novel Les liaisons dangereuses (1782).
Its path to modern popularity may begin with the 1949 film Kind Hearts and Coronets which had revenge is a dish which people of taste prefer to eat cold. The familiar wording appears in The Godfather by Mario Puzo (1969) and is quoted as if from an "old Klingon Proverb" in the film Star Trek II: The Wrath of Khan (1982) and in the title sequence of the Quentin Tarantino film Kill Bill: Vol 1 (2003).
Another proverb states: "Before you embark on a journey of revenge, dig two graves." The implication here is that a desire for revenge may ultimately hurt the seeker as much as the victim. Alternatively, it may imply that you should be prepared to die yourself in the process of seeking revenge.