A dissertation or thesis is a document submitted in support of candidature for an academic degree

Academic degree

An academic degree is a position and title within a college or university that is usually awarded in recognition of the recipient having either satisfactorily completed a prescribed course of study or having conducted a scholarly endeavour deemed worthy of his or her admission to the degree...

 or professional qualification presenting the author's research

Research

Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 and findings. In some countries/universities, the word "thesis" or a cognate is used as part of a bachelor's

Bachelor's degree

A bachelor's degree is usually an academic degree awarded for an undergraduate course or major that generally lasts for three or four years, but can range anywhere from two to six years depending on the region of the world...

 or master's

Master's degree

A master's is an academic degree granted to individuals who have undergone study demonstrating a mastery or high-order overview of a specific field of study or area of professional practice...

 course, while "dissertation" is normally applied to a doctorate

Doctorate

A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...

, while in others, the reverse is true.

The term dissertation can at times be used to describe a treatise

Treatise

A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.-Noteworthy treatises:...

 without relation to obtaining an academic degree.