Sector (noun)

1. A distinct area or division of a field, industry, or market.
2. A division of an economy or society.

Origin:

Late middle english (in the sense "a dividing line or boundary"): from latin sectōr, from secare "to cut". .

Examples:

1. The retail sector is experiencing a slowdown.
2. The technology sector is one of the fastest growing sectors of the economy.
3. The public sector employs many people in the community.
4. The private sector is responsible for the majority of jobs in the country.
5. The service sector is an important part of the economy.