A business model describes how your company creates, delivers and captures value. A business model is designed to change rapidly to reflect what you find outside the building in talking to customers. It’s dynamic and it reflects the iterative reality that startups face. Business models allow agile and opportunistic founders to keep score of the pivots in their search for a repeatable business model.
— Steve Blank

Source: Part I: Validate Your Business Model Start With a Business Model, Not a Business Plan – The Accelerators – WSJ