What is the term for a large settlement consisting of very poor quality housing?

The term that best describes a large settlement consisting of very poor quality housing is shanty towns. Shanty towns are typically characterized by inadequate housing, lack of basic services like clean water, sanitation, and electricity, and are often constructed from scavenged materials. They usually arise in urban areas where there is rapid population growth and a lack of affordable housing options, leading people to create their own makeshift homes.

While slums also refer to areas with poor housing and living conditions, the term "shanty town" is more specific to informal settlements that are often found at the outskirts of urban areas. Ghettos, on the other hand, refer to areas predominantly inhabited by a specific ethnic group, often as a result of social or economic discrimination. The informal sector refers to economic activities that are not regulated by the government, which may include a variety of jobs but does not specifically address the condition of housing.

Thus, shanty towns aptly capture the essence of large settlements that are marked by poor housing quality and associated challenges.