Whether you are writing a short essay or a doctoral dissertation, your thesis statement will arguably be the most difficult sentence to formulate. This wikiHow will guide you through the process of writing one.
1. Determine the type, purpose, and audience of your paper.
2. Ask a question, then make the answer your thesis statement.
3. Take a stance, then ensure that it is provable.
4. State it two parts: a clear topic and a brief summary of what you will say.
5. Limit the thesis to one or two sentences.
A thesis or dissertation  is a document submitted in support of candidature for an academic degree or professional qualification presenting the author''''s research and findings.  In some contexts, the word "thesis" or a cognate is used for part of a bachelor''''s or master''''s course, while "dissertation" is normally applied to a doctorate, while in other contexts, the reverse is true.  The term graduate thesis is sometimes used to refer to both master''''s theses and doctoral dissertations. 
The required complexity or quality of research of a thesis or dissertation can vary by country, university, or program, and the required minimum study period may thus vary significantly in duration.
An essay is, generally, a piece of writing that gives the author's own argument — but the definition is vague, overlapping with those of an article , a pamphlet , and a short story. Essays have traditionally been sub-classified as formal and informal. Formal essays are characterized by "serious purpose, dignity, logical organization, length," whereas the informal essay is characterized by "the personal element (self-revelation, individual tastes and experiences, confidential manner), humor, graceful style, rambling structure, unconventionality or novelty of theme," etc. 
The concept of an "essay" has been extended to other mediums beyond writing. A film essay is a movie that often incorporates documentary filmmaking styles, and focuses more on the evolution of a theme or idea. A photographic essay covers a topic with a linked series of photographs that may have accompanying text or captions.