Sparse population density means that there are very few people spread over a large area. In this case, it indicates low population density relative to the size of Western Sahara.
Related terms
Population Distribution: Population distribution refers to how people are spread out across an area or region.
Demographics: Demographics involve studying statistics about human populations, including factors such as age, gender, occupation, education level, etc.
Urbanization: Urbanization refers to the process by which rural areas become more urban or city-like due to migration from countryside areas into cities.