A set is a certain section of a gang that is commanded by a different leader than other sets; they are practically independent from the gang they belong to. They are usually named for the neighborhood they are assigned to, and control the area and make their own rules, not the leader of the gang. The sets sometimes fight each other, if they get into disagreements.
Gangs were the first to introduce sets to the mob world. Since gangs have no organized structure, they give their top-ranking members territories and groups of men, who become a "set", branching off from the main family and other sets. Because of this, sets often fight each other. Notable examples of quarrelling sets include the Grove Street Families and Seville Boulevard Families, both part of the Grove Street Families Gang from Ganton. However, their rivals, the Ballas, had the Front Yard Ballas, Rolling Heights Ballas, Kilo Tray Ballas, and Temple Drive Ballas, who were often on friendly terms.