What are some example artifacts from product definition?

In the olden days, when waterfall development was still practiced, product definition is done entirely by product managers, and usually involve these deliverables. No one does it this way anymore by the way.

• Market Requirements Document - a document that outlines the business case for the product, including the target segment, the buyer and user personas, the high level problem and solution, as well as the unit economics for that product.
• Product Requirements Document - a document that provides details on the proposed solution, outlining the primary use cases, the high level product architecture, and a preliminary feature list. 
• Functional Specifications - a document that provides full details on each and every feature to be included in any product release.

There are more documents to be generated by engineering once all that is generated by product management including technical specifications (translating what the user sees from what is measurable from an engineering and engineering testing standpoint), software or hardware design documents (outlining the design of specific features) and so forth.

Today, no organization that adheres to this slow and cumbersome process can keep up with the rapidly changing market conditions.  Instead, most people take a much more nimble approach to product definition.  The high level needs are still the same - capturing the beachhead market and TAM as well as the business case still needs to be done.  The product's rough feature set still needs to be defined.  The artifacts generated, however, are much more granular and is generally easier to digest and allows much more room for iterations and better autonomy for the designer and engineer to collaborate on specific features.

Following is a list of some of the common, modern artifacts generated in the process of defining a product.

• Positioning Statement
• Competitive 2x2
• User Persona(s)
• Buyer Persona(s)
• High level product specifications (one page)
• Product roadmap
• Release planning checklist
• Workflows and storyboards (user centric)
• User stories (user centric)
• UX Flow chart example
• Wireframe examples
• Graphical composition examples