What is the difference between Book Building Issue and Fixed Price Issue?

Initial Public Offering can be made through the fixed price method, book building method or a combination of both.Difference between shares offered through book building and offer of shares through normal public issue (Source: BSE): Features Fixed Price process Book Building process PricingPrice at which the securities are offered/allotted is known in advance to the investor.Price at which securities will be offered/allotted is not known in advance to the investor. Only an indicative price range is known. DemandDemand for the securities offered is known only after the closure of the issue.Demand for the securities offered can be known everyday as the book is built. PaymentPayment if made at the time of subscription wherein refund is given after allocation.Payment only after allocation