Find out about primary, secondary and tertiary economic activities and which jobs fit which category. People and places -Human geography - Earning a living Learning Points Primary economic activities involve gathering raw materials. Secondary economic activities involve manufacturing goods. Tertiary economic activities sell goods or provide a service. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.