There are four main types of industry: primary ... decided to move from the secondary sector to a new phase of post-industrialism, where the tertiary and quaternary sectors were encouraged.

All industry is part of a chain that starts with primary industry ... will focus around this sector. A short film for secondary schools explaining tertiary and quaternary industries: what they ...

Primary agricultural ... nature or from the primary sector. Secondary agricultural goods are treated products and preparations from primary agricultural goods. Together, these form the main definition ...