Translational research is a phenomenally complex topic, but generally refers to the basic idea of taking discoveries made in basic research and researching how they apply "in the real world". It's worth noting that this (usually) does not mean applied research, although the basic concepts are pretty similar in a lot of ways. The main difference is that transitional research paradigms reject the dichotomy between basic and applied research when doing so. "Basic" research within a translational research paradigm both informs and is informed by "applied" research, blurring the lines between the two.
Any more complex explanation of research paradigms in this context, however, would require an explanation of the field of medical informatics. Frankly, I don't want to go there.
I will admit that I have some reservations and concerns regarding the entire translational research paradigm. I will also admit that there is a good chance that this is because of the limitations to my understanding of it. It is quite possible -- even probable -- that my concerns and reservations have been addressed.
Of course, it also doesn't help that there isn't a standardized definition of "translational research", and some definitions conflict -- often in major ways -- with the above (e.g. this one).
Most people, however, don't need to really understand research paradigms. What they need to understand -- even if only in general terms -- are the challenges that those paradigms were designed to address.
Simply put -- as impressive as modern medical science is, we really don't understand that much about how the human body works. This is why most "promising new treatments" turn out to be worthless -- or, all too often, worse than worthless. It's the aspects of biology that we don't understand that keep tripping us up, time after time after time.
This is why any new treatment has to be tested -- thoroughly. This is why rushing the process is a very bad idea. It's also why many of the medications we use have nasty side effects.
Simply put: as much as we'd like to believe otherwise, modern doctors, pharmacists, and so on don't really know what they're doing.