You may be asked to use a number of different types of sources including Primary, Secondary, or Tertiary:
Primary Sources
Primary Sources consist of original materials--a first-hand account of something. This information has not been filtered through interpretation. Examples of primary sources include:
an original journal or diary
a novel, poem or play
original notes from an experiment or original research
an original letter
a piece of artwork or furniture, musical score, or theatrical performance
Secondary Sources
Secondary Sources are written after something has happened and has the benefit of hindsight. This information includes interpretations and evaluations of primary information. Examples of secondary sources include:
a critique of a poem, play, or piece of literature
a history book based on primary historical sources
a scientific report based on experimental notes
commentaries and criticisms
biographical works
Tertiary Sources
Tertiary Sources are a distillation and collection of primary and secondary information. They usually include or are based on a range of secondary sources. Examples of tertiary sources include: