Mike Cohn's presentation discusses user stories and why they are useful for software requirements and development. User stories address the communication problem between stakeholders who want software built and developers who build it. They help balance requirements between business and technical needs. Stories also help with resource allocation and handling imperfect schedules. Stories are written in a simple format of "As a <user>, I want <goal> so that <benefit>" and details are discussed. Stories support iterative development and help ensure the final product meets user needs.