When searching for information on a topic, it is important to understand both primary and secondary sources.

1. Primary sources are those that present original, unedited information. They could be data -- e.g. statistics, empirical research, results from experiments; written accounts of instances -- e.g. letters, diaries, newspaper accounts; or the actual items themselves -- a historical document, a book, a play. They should be original and unedited. A Primary source requires the learner to interact with the source and extract information.
2. Secondary sources have a degree of separation from Primary sources. They utilize Primary sources to analyze, evaluate, synthesize and/or merge data. For example, they can introduce someone's interpretation of previously published data set, or their opinion/review of a particular play, book or piece of music. Secondary resources do not rely upon direct observation or participation. In fact, they may even rely on other Secondary resources in their formation.

Primary sources tend to stand on their own, while secondary sources are based on other sources; however, it is not always easy to discern the difference between the two. For example, the same exact document may be considered a primary source to one researcher and a secondary source to another.