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.
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.
Despite the burgeoning technologies in the field of "helping", on many levels psychotherapy is still a crapshoot. Some of the goal of training, I think, is to help students accept that fact. The work is part science, part art, and part luck. Learning to tolerate the anxiety inherent in that recipe is critical for any clinician.
Martha Manning, in Undercurrents (1st edition ed.). HarperCollins. 1995. pp. p. 9