For the last fifty or so years venture capital in the US refers to investments in high potential return, high risk companies by professional organizations. Most commonly venture capital firms are private limited partnerships but there are also corporate venture capital organizations (such as Intel Capital Corp.) and public/private venture capital organizations (such as Maine Venture Fund).
There is a somewhat fuzzy border between venture capital and angel investment. Before World War II all venture capital was invested by wealthy individuals (but we’re not sure what it was called back then). And now so-called “super angels,” “Angelist syndicates” and “angel investment funds” blur the line. In some countries what is called venture capital may be the same as angel investment in the US.
There is also a somewhat fuzzy border between venture capital and private equity. Technically speaking all venture capital is also private equity (it’s equity investment in private companies), but in general private equity investments are made in more mature businesses than venture capital. How do you draw the maturity line? That’s where it gets fuzzy.
And there is a somewhat fuzzy border between venture capital and hedge funds. The latter are also professional investors, and many have freedom to invest just about anywhere. Sometimes hedge funds invest in companies that otherwise might take investments from venture capital firms.
Finally there is a fuzzy border when debt is injected into riskier, high growth potential, innovative companies. In the US Small Business Investment Companies (SBICs) operate in that niche. Are they venture capital? Some may think so.