An insurgency is a violent armed rebellion by small lightly armed bands who practice guerrilla warfare from primarily rural base areas against a larger authority. The key descriptive feature of insurgency is its asymmetric nature: small irregular forces face a large well-equipped regular military force state adversary. Due to this asymmetry insurgents avoid large-scale direct battles opting instead to blend in with the civilian population (mainly in the countryside) where they gradually expand territorial control and military forces. Insurgency frequently hinges on control of and collaboration with local populations.