The short answer
Startup equity on paper is real in the sense that it may be worth a lot someday, but you cannot spend it, and its value is a guess until there is a real transaction. Private shares are illiquid, hard to value, and can go to zero. So it is wiser to treat that number as potential, not net worth you can rely on. What is real is what you could access if you needed money next month: cash, liquid investments, anything outside the company. Founders who confuse the two can feel rich while being one bad quarter from stress at home. The Holloway and Carta guides to equity explain how private equity is valued and why paper value is not money in hand. This is general education, not advice, and equity valuation and tax rules change, so confirm specifics with a CA or a qualified advisor.
A curated summary to orient you, not advice. The resources below are the real value.