Business
Business is the activity of making one's living or making money by producing or buying and selling goods or services. Simply put, it is "any activity or enterprise entered into for profit. It does not mean it is a company, a corporation, partnership, or have any such formal organization, but it can range from a street peddler to General Motors." The term is also often used colloquially (but not by lawyers or public officials) to refer to a company, but this article will not deal with that sense of the word.
Management
Management (or managing) is the administration of an organization, whether it is a business, a not-for-profit organization, or government body. Management includes the activities of setting the strategy of an organization and coordinating the efforts of its employees (or of volunteers) to accomplish its objectives through the application of available resources, such as financial, natural, technological, and human resources. The term "management" may also refer to those people who manage an organization.
Project Management
Project management is the practice of initiating, planning, executing, controlling, and closing the work of a team to achieve specific goals and meet specific success criteria at the specified time. A project is a temporary endeavor designed to produce a unique product, service or result with a defined beginning and end (usually time-constrained, and often constrained by funding or staffing) undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value. The temporary nature of projects stands in contrast with business as usual (or operations), which are repetitive, permanent, or semi-permanent functional activities to produce products or services. In practice, the management of such distinct production approaches requires the development of distinct technical skills and management strategies.
Psychology
Psychology is the science of behavior and mind, including conscious and unconscious phenomena, as well as feeling and thought. It is an academic discipline of immense scope and diverse interests that, when taken together, seek an understanding of the emergent properties of brains, and all the variety of epiphenomena they manifest. As a social science it aims to understand individuals and groups by establishing general principles and researching specific cases.
Management
In the long-run the workman may be as necessary to his master as his master is to him, but the necessity is not so immediate.
Adam Smith (1776) The Wealth of Nations Chapter VIII, p. 80
Management
Poorly managed corporations, disorganized businesses, and badly led service agencies experience crisis daily and most will eventually fail. In contrast, the danger is to well organized, smooth running institutions that may not recognize a building crisis. Too often, sound organizations rely on their normal modus operandi to pull them through a crisis. It might. But at what cost? And what if it does not pull them through?
Wheeler L. Baker, Crisis Management: A Model for Managers (1993), p. 6
Business
I believe that leaders and leadership teams working together in a proper design will run the business more effectively than by hierarchical, command-and-control managing. But I can't prove that. And there are no models.
Marvin Bower (1966) The Will to Manage p. 7.