Squatters settle on land, especially public or unoccupied land, without legal right or title, whereas slums refer to highly congested urban areas marked by deteriorated housing and living conditions. The UN defines slums as neglected parts of cities with appallingly poor living conditions lacking basic services. While strategies in the past tried to address slums through public housing and upgrading, problems have grown due to various issues such as lack of funding, interest, and tenure security for squatters. Effective slum upgrading requires local participation, affordability, sustainability, and provision of basic infrastructure like sanitation, roads/drainage, and water supply.