What is interactive about it?
The defining feature is not the file format. It is the relationship between information and the product. A user may rotate the product, select a component, follow hotspots, move through guided steps, and view a component together with its explanation.
What kinds of information fit 3D best?
3D is particularly useful when spatial relationships matter: product structure, component location, assembly order, disassembly sequences, part identification, operating positions, and maintenance access points.
Is an interactive 3D manual the same as a digital manual?
Not necessarily. “Digital manual” can describe PDFs, web documentation, searchable systems, and interactive experiences. An interactive 3D product manual is one specific approach within that broader category. See Interactive 3D Product Manual vs PDF Manual.
When is it useful?
The strongest fit is a product where users need to understand more than a list of instructions: complex assemblies, identifiable components, service and maintenance procedures, or technical products with important spatial relationships.
What it is not
It is not simply a PDF converted into a web page. It also should not force 3D into information that is clearer as text, tables, specifications, or conventional documents.
How should a project be scoped?
Start with the existing information. Identify which product areas need explanation, which steps are difficult to understand, which components need identification, and which existing diagrams or manuals are useful. The goal is to find where interactive visualization makes information easier to understand. If the scope question is still open, how to create interactive product documentation sets out the structure and sequence.