Essays can consist of a number of elements, including: literary criticism, political manifestos, learned arguments, observations of daily life, recollections, and reflections of the author. Almost all modern essays are written in prose, but works in verse have been dubbed essays (e.g. Alexander Pope's An Essay on Criticism and An Essay on Man). While brevity usually defines an essay, voluminous works like John Locke's An Essay Concerning Human Understanding and Thomas Malthus's An Essay on the Principle of Population are counterexamples. In some countries (e.g., the United States and Canada), essays have become a major part of formal education. Secondary students are taught structured essay formats to improve their writing skills, and admission essays are often used by universities in selecting applicants and, in the humanities and social sciences, as a way of assessing the performance of students during final exams.
The concept of an "essay" has been extended to other mediums beyond writing. A film essay is a movie that often incorporates documentary film making styles and which focuses more on the evolution of a theme or an idea. A photographic essay is an attempt to cover a topic with a linked series of photographs; it may or may not have an accompanying text or captions.
Most startups that raise money do it more than once. A typical trajectory might be (1) to get started with a few tens of thousands from something like Y Combinator or individual angels, then (2) raise a few hundred thousand to a few million to build the company, and then (3) once the company is clearly succeeding, raise one or more later rounds to accelerate growth.
Reality can be messier. Some companies raise money twice in phase 2. Others skip phase 1 and go straight to phase 2. And at Y