According to the UN's Integrated Operational Guide to DDR Standards (IDDRS), DDR seeks to create security and stability in post-conflict environments, and to start recovery and development, by getting the former combatants to comprehensively disarm and providing them with opportunities for sustainable social and economic reintegration into civilian life. The disarmament process includes the collection, documentation, control and disposal of small arms and light weapons (SALW) and ammunitions of combatants.
Demobilisation is a support for the formal and controlled discharging of active combatants from armed forces and/or other armed groups, leading to a reinsertion process where combatants receive assistance (e.g. short-term education, medical services, clothes, food, etc.) during demobilisation but prior to the longer-term process of reintegration. Through the reintegration process, combatants receive support toward gaining sustainable employment and income. This usually takes place in communities at the local level over a longer time span.
Security sector reform is a more dynamic and comprehensive task. Many states after civil wars lack the structures and mechanisms necessary to ensure the physical security of its people and the country itself. Norms and orders to maintain security are absent. Security sector institutions like the armed forces and the police no longer serve the function of protecting the people but, instead, often threaten them with robbery, human rights abuses, and other criminal acts.
Security sector reform in the post-conflict situation therefore attempts to reverse these situations. Post-conflict security sector reform has three major objectives. Firstly, it (re)builds security sector institutions more efficiently and effectively. Security sector institutions here refer to those institutions that possess a legitimate monopoly on the use of force for the purpose of providing security to the people.
They may include the armed forces, the police force, paramilitary groups, border patrols, and private security companies, amongst others. Typically, in the early stages of security sector reform, it eliminates the sources of any possible resurgence of violence, particularly through DDR of both state and non-state combatants. In many cases, the first SSR task for post-conflict peace support operations is the construction of security sector institutions from scratch, as in Afghanistan and East Timor, or the reconstruction of the already existing institutions while incorporating some demobilised former combatants, as in South Africa and Angola. Longer-term SSR agendas include measures to downsize the armed forces, recompose the balance of the staff and officers depending on the complexity of ethnicities, tribes, and gender in a given post-conflict state.