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 occurs when customers find significant value in the product, leading to increased sales and customer satisfaction. Achieving this fit is crucial for a business's growth and sustainability. To determine if a company has achieved Product Market Fit, founders often look for indicators such as strong customer retention, positive feedback, and a growing user base. It signifies that the product resonates well with its target audience, making it easier to scale and expand within the market.