I haven’t explained what the differences are because almost everything is different. It’s like comparing a Model T to a Bugatti. They’re simply not built the same way, even if they both use internal combustion engines and gearboxes.
Let me give you an overview of how the research pipeline occurs though. First is the fundamental research, which outside of semiconductors is usually funded by public sources. This encompasses things like methods of crack formation in glasses, better solid state models, improved error correction algorithms and so on. The next layer up is applied research, where the fundamental research is applied to improve or optimize existing solutions / create new partial solutions to unsolved problems. Funding here is a mix of private and public depending on the specific area. Semiconductor companies do lots of their own original research here as well, as you can see from these Micron and TSMC memory research pages. It’s very common for researchers who are publicly funded here to take that research and use it to go start a private company, usually with funding from their institution. This is where many important semiconductor companies have their roots, including TSMC via ITRI. These companies in turn invest in product / highly applied research aimed at productizing the research for the mass market. Sometimes this is easy, sometimes it’s extremely difficult. Most of the challenges of EUV lithography occurred here, because going from low yield academic research to high yield commercial feasibility was extremely difficult. Direct investment here is almost always private, though there can be significant public investments through companies. If this is published (it often isn’t), it’s commonly done as patents. Every company you’ve heard of has thousands of these patents, and some of the larger ones have tens or hundreds of thousands. All of that is the result of internal research. Lastly, they’ll take all of that, build standards (e.g. DDR5, h.265, 5G), and develop commercial implementations that actually do those things. That’s what OEMs buy (or try to develop on their own in the case of Apple modems) to integrate into their products.