Different assignments and research interests all require different types of sources. Sources can be categorized as primary, secondary, or tertiary sources.
Primary sources are first-hand accounts of an event or topic, created by people directly connected to it.
Examples of primary sources include:
Secondary sources interpret, evaluate, or analyze primary sources.
Examples of secondary sources include:
Tertiary sources index, abstract, organize, and otherwise compile other sources.
Examples of tertiary sources include: