tl;dr: Too Long, Didn't Read. Of course you didn't read the 300-page use case bible "Writing Effective Use Cases" (on Amazon), the 200-page complete "Unifying Use Cases, User Stories, Story Maps" (on this site), or even the short 80-page "Mini-Book on Use Cases" (on this site) - or your colleagues didn't. So here is - for free - on 1 page. The ultra-short synopsis, everything you really need to know, if a form you can crib from, read, and send to your colleagues.

Part of a 5-TL;DR sequence answering the questions everyone asks:

What is a use case?

What is a user story?

What's the difference between a use case and a user story?

What's a story map?

When and how do you use them all together, the use cases, the user stories, the story map?

You can find each sheet here separately, or get the 5-page bundle, for free. Go and get the original source books from me, or Ivar Jacotbson, or Jeff Patton, or Mike Cohh when you want to dig into the details.

Dr. Cockburn was named "On of the 42 Greatest Software Professionals of All Times." A world expert on methodologies, project management, software architecture, use cases and agile development, he co-authored both the Agile Manifesto and the Project Management Declaration of Inter- dependence. He was one of the leading methodologists in the new area of object-oriented design in the early 1990s. Hired by the IBM Consulting Group to create their methodology for object-technology projects, he taught the entire design team on a live project all they would need to know to run the project they were embarking on. It was a tour-de-force of project education, complete from project management tips to requirements gathering to software design. It set the stage for modern "agile" development techniques. It was in that work thta he studied all of these techniques, discussing with the various authors as they developed their ideas. These TL;DR sheets are summaries of 20-30 years of discussion and use.