Street fighting is a colloquial term used to denote unsanctioned, usually illegal, hand-to-hand fighting in public places, between individuals or groups of people.
Unlike sport fighting, a street fight might involve weapons, multiple opponents or revenge and has no rules. The venue is usually a public place, e.g. a street, and the fight often results in a serious injury or even death.
The main difference between street fighting and self-defense is, that a street fight is avoidable, whereas a self-defense situation is not. A typical scenario might involve two men arguing in a bar, then one suggests stepping outside where the fight commences. Thus, it is often possible to avoid the fight by backing off, while in self-defense, a person will not know
they are about to be attacked until it happens.
In the Martial Arts community, street fighting and self-defense are often considered synonymous.