In cities and towns around the world a significant proportion of residents are tenants. For various reasons millions of people in developing and developed countries rent, rather than own, the housing unit in which they dwell. For instance, low-income households who cannot presently meet the expense of home ownership, recent urban migrants who prefer centrally located rental accommodation that gives them flexibility, young people who value mobility, and individuals who choose to spend their money on other priorities rather than home ownership are only a few of the characteristics and motivations of tenants.

For millions of people rental housing provides a significant source of income. While there are commercial, public-sector, social, and employer rental property landlords, in cities of the developing world the largest group of landlords are the small-scale landlords who supply rental accommodation, often as part of their self-built house, to generate a regular source of income and provide financial security during old age.