Private equity is ownership or interest in entities that aren't publicly listed or traded. A source of investment capital, private equity comes from firms that buy stakes in private companies or take control of public companies with plans to take them private and delist them from stock exchanges.

A portfolio is a collection of funds (or sometimes other investments) owned by an individual. A fund is a pool of investments (usually shares) that is managed by a professional fund manager.

In an Active portfolio, Portfolio Managers strategically buy and sell the stocks and assets to beat the market returns. Mutual Fund is a type of investment instrument that is made up of a pool of money collected from various investors to invest in stocks, bonds, and other assets.

A portfolio company is simply a company that a private equity firm invests in and continues to hold an interest in. Private equity firms are essential for a portfolio company. Examples of portfolio companies include family offices, pension funds, sovereign wealth funds and insurance companies.

Stocks and bonds are generally considered a portfolio's core building blocks, though you may grow a portfolio with many different types of assets—including real estate, gold, paintings, and other art collectibles. Diversification is a key concept in portfolio management.

A portfolio company is a company (public or private) that a venture capital firm, buyout firm, or holding company owns equity. In other words, companies that private equity firms hold an interest in are considered portfolio companies.

A manager who manages assets for a large money management institution is commonly referred to as a portfolio manager, while someone who manages smaller fund assets is typically called a fund manager.