An innovation is an idea which results in a business
You can categorize and grade it. In most cases this is a question of the level and the importance of an innovation. The highest level might be something like the idea to use mildes to create Penicillin. This a breakthrough innovation.
There is also a second category. That's the time to market. Think about the flat screen TV and how fast the x-ray-tube disappeared or Kodak lost its negativ film and slide business.
My project on Corporate Creativity and Innovation, available at https://www.researchgate.net/project/Corporate-Creativity-and-Innovation, ought to be relevant and of interest. The project showcases 28 references, including articles on business model innovation, innovations in management, innovation in the public sector, and social innovation.
The question of 'What is innovation?' has no answer as the scholarly views are quite heterogenous.They tend to agree on 'Change & Novelty" as its main characteristic, but that is all. I found more than 250 different definitions of the notion of Innovation.
The question 'What is the Nature of Innovation' is the focus of my ongoing reearch project (see https://www.researchgate.net/project/Nature-of-Innovation for description). The project has tow main parts: (1) case studies of 'real world' inventions/innovations, and (2) the views, theories and definitions of Innovation Scholars (like Schumpeter, Freeman, etc.) who looked at these real world innovations and developed their Views, Theories, Models and Definitions.
The real world research focusses on technological innovation with case studies of electric inventions/innovations (electric light, telegraph telephone, etc.). Seven case studies are published (see: https://www.amazon.co.uk/B.-J.G.-van-der-Kooij/e/B00SUS2RZA). In addition I wrote some articles on the influence of the General Purpose Technology of Electricity (eg the Invisible Hand of Innovation). Open acces Working papers are available on https://repository.tudelft.nl/islandora/search/b.j.g.%20van%20der%20kooij%20?collection=research
A 1988 analysis (that was updated in 2013) presented some 80 different definitions of Innovation. (see: https://repository.tudelft.nl/islandora/object/uuid%3A6a5624c9-e64e-4426-98e9-f239f8aaba18?collection=research). Today I have a collection of over 250 (the above mentioned defintion by Heine is 251), but did not publish on it yet (a book is in the process of making).
In the above mentioned survey I proposed a general definition of innovation (see Epiloque). Maybe this gives you some food for thought. Contact me on [email protected] if you want more info.