Background sources such as, but not limited to, dictionaries and encyclopedias provide context for your topic or even help you choose one. Researchers use them when they need:
A brief overview of a topic
Definitions of terminology
Important issues, figures, dates, and/or events for a topic
Sources for further research in the form of bibliographies
Engineering is part of almost everything we do - from the water we drink and the food we eat, to the buildings we live in and the roads and railways we travel on. This Very Short Introduction explores the nature and practice of engineering, its history, its scope, and its relationship with art, craft, science, and technology. It considers the role of engineering in the modern world, demonstrating its need to provide both practical and socially acceptable solutions, and explores how engineers use natural phenomena to embrace human needs.
A comprehensive dictionary of terms for engineering students containing significant numbers of entries, Dictionary of Engineering Terms, Butterworth-Heinemann covers the areas of engineering science, electrical and electronic engineering, workshop practices and mechanical engineering.