Which of the insurgency elements do the actual fighting an provide security?

In an insurgency, the elements that typically engage in actual fighting and provide security are the armed factions or militant groups. These groups often consist of combatants who are trained and organized to carry out attacks against government forces or rival groups. They may also establish local security mechanisms to protect their communities and maintain control over territory. Additionally, these elements can garner support from the local population through provision of security and basic services.