Impact can be divided into several categories and can include both economic and societal impacts - below is the European Science Foundation (ESF) classification of impact. Most research projects will have impacts in multiple areas.
Contribution to understanding of ideas and reality, values and beliefs.
Contribution to the sale price of products, a firm's costs and revenues (micro level), and economic returns either through economic growth or productivity growth (macro level).
Contribution to the management of the environment, for example, natural resources, environmental pollution, climate and meteorology.
Contribution to public health, life expectancy, prevention of illnesses and quality of life.
Contribution to how policy makers act and how policies are constructed and to political stability.
Contribution to the subsequent progress of knowledge, the formation of disciplines, training and capacity building.
Contribution to community welfare, quality of life, behaviour, practices and activities of people and groups.
Contribution to the creation of product, process and service innovations.
Contribution to curricula, pedagogical tools, qualifications.
The UCD College of Engineering and Architecture has produced a number of impact case studies relating to research from the College.
You can view them here.