Understandings of innovation usually encompass multiple overlapping aspects, putting innovation terminology at risk of vagueness and overuse. However, innovation concepts are expected to remain powerful and useful in healthcare beyond the pandemic and into the future, so clarity will be helpful for effective leadership. To disentangle and disambiguate meanings within innovation, we offer a framework that captures and simplifies foundational substance within innovation concepts. Our method is an overview review of innovation literature from the 5 years preceding COVID-19. 51 sources were sampled and analysed for explicit definitions of healthcare innovation. Drawing on broad themes suggested from previous reviews, and gathering specific themes emergent from this literary dataset, we focused on categorising the nature of innovations (the what) and reasons given for them (the why). We identified 4 categories of what (ideas, artefacts, practice/process and structure) and 10 categories of why (economic value, practical value, experience, resource use, equity/accessibility, sustainability, behaviour change, specific-problem solving, self-justifying renewal and improved health). These categories reflect contrasting priorities and values, but do not substantially interfere or occlude each other. They can freely be additively combined to create composite definitions. This conceptual scheme affords insight and clarity for creating precise meanings, and making critical sense of imprecision, around innovation. Improved communication and clear shared understandings around innovative intentions, policies and practices cannot but improve the chances of enhanced outcomes. The all-inclusive character of this scheme leaves space for considering the limits of innovation, and notwithstanding well-established critiques, provides a basis for clarity in ongoing usage.