A dissertation or thesis[1] is a document submitted in support of candidature for a degree or professional qualification presenting the author's research and findings.[2] In some countries/universities, the word thesis or a cognate is used as part of a bachelor's or master's course, while dissertation is normally applied to a doctorate, whilst, confusingly, in others, the reverse is true.

The term "dissertation" can also mean, more in general, a treatise on some subject, without relation to obtaining an academic degree. The term "thesis" can also mean the central claim of an essay or similar work.