The term sector means different things to different people. The basic economic definition of a sector is a 'homogenous group of productive economic activities'. The most common set of sectors is found in national accounts data.
Economists define sectors in terms of their output.
This definition of sectors is very broad, as an examination of the transport sector shows. Each of these sub-sectors could be further divided between passengers and goods, and long and short haul. The term 'sector' is used by people other than economists. These included agriculture, livestock, fisheries, private sector, tourism, infrastructure and transport, research, education, public health, family planning, problems of drugs, potable water, rural development, urban development, tropical forestry sector, environment, women and development, population, regional integration, institutional reform, poverty alleviation, and social development. As much support is given on a sectoral basis, it is both appropriate and necessary to look at the impact AIDS might have by sector.