The core idea behind DCF: a company is worth the sum of all the cash it will ever generate for its owners, adjusted downward ('discounted') because money you receive years from now is worth less than money in hand today. Analysts build a model projecting a company's future cash flows for several years, then estimate a value for everything beyond that, and discount it all back to a single number: 'what this company is worth today.' It's a genuinely useful framework, but it's only as good as its assumptions — small changes in the assumed growth rate or discount rate can swing the resulting value dramatically, which is why two analysts can look at the same company and get very different DCF valuations.