Earlier quoted context omitted.
Not sure. The D in R&D stands for, I imagine, development of the business, whereas the one in software development stands for development of software.
> Research and development is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existing ones. https://en.wikipedia.org/wiki/Research_and_development
https://www.irs.gov/pub/irs-regs/research_credit_basic_sec41...
(Not 100% sure this is the most up to date definition but it gives you an idea)