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.
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.