Product-Market Fit refers to the stage in a startup's development where a product successfully meets the needs and demands of a specific market. This alignment indicates that customers find value in the product, leading to increased sales and customer satisfaction. Achieving this fit is crucial for a business's growth and sustainability. When a company reaches Product-Market Fit, it often experiences rapid growth, as satisfied customers become advocates, driving word-of-mouth referrals. This concept is essential for entrepreneurs and investors, as it helps identify whether a product has the potential for long-term success in its target market, such as in the case of Silicon Valley startups.