In general, there are three types of sources of information: primary, secondary, and tertiary. It is important to understand these information types and to know when each source is appropriate to use in coursework.
Primary Sources
Primary sources are original materials on which other research is based. These sources are usually a document or result that is being reported first hand. Primary sources are original sources that are not interpretations made by someone else.
Examples of Primary Sources
Secondary Sources
Secondary Sources are sources that describe or analyze primary sources. These sources value, discuss, or comment on the primary source, and use primary sources to create their own work.
Examples of Secondary Sources
Tertiary Sources
Tertiary Sources are used to organize and locate primary and secondary sources. These sources summarize and compile fact and knowledge produced by others. Tertiary sources often assemble both primary and secondary sources together, and are used for quick access to facts. Note that not all sources within this category are suitable for scholarly writing.
Examples of Tertiary Sources