Essay generally refers to short essays/course papers of several thousand words, which usually only contains literature review and critical analysis, and there can be no independent data and evidence (even if there is one, it is simplified).
Dissertation refers to the master's thesis in British English. A doctoral thesis is a thesis.
Dissertations are generally 1-20000 words, and usually have independent research methods, data analysis and other empirical content. Papers are generally at the level of 654.38+ 10,000 words, which requires systematic research methods, field investigation, data analysis and other empirical research.
Generally speaking, the main difference between a dissertation and a thesis lies in whether there is a complete empirical process such as research methods and data analysis. Whether an article contains independent data analysis depends on the context. For example, articles published in conferences and magazines can also include research methods and data analysis, while some course papers cannot.
By the way, the number of words in English is usually more than twice that in Chinese. Therefore, it is not easy to write an English paper with more than 1000 words. (such as an a, translated into Chinese is the word "one". Indispensable is a word in English, and five words in Chinese are "indispensable". =)