Financial modeling involves creating an abstract representation of a real-world financial situation to project and forecast future performance based on historical data and assumptions. The primary objectives are to project and forecast a company's historical performance and assumptions about the future. Essentials to building effective models include following standard formats, maintaining proper spreadsheet design with appropriate headings, organizing assumptions documentation, and facilitating data entry in one place. Financial models are used across various industries and roles such as business planning, investment banking, credit ratings, and mergers and acquisitions.