The term "portfolio companies" refers to a group of companies that are owned or invested in by an investment firm, venture capitalist, or private equity firm. These firms typically manage multiple portfolio companies as part of their investment strategy and provide funding, support, and guidance to help these businesses grow and succeed. The phrase "portfolio" is used because it's similar to how an individual might manage a diverse set of financial assets or investments in a single portfolio, with the goal of maximizing returns while minimizing risk. In this context, each company within the portfolio represents a unique opportunity for growth and profitability, and the overall success of the portfolio is measured by the collective performance of its individual components.