Hard to explain without being a pathologist, and getting into other areas, some I have difficulty with, but believe their talking about the histology features of the oropharynx as being Keratinized or Non Keratinized Squamous Cell Carcinoma as it may apply to HPV positivity and negativity, effecting the nuclei or not, which Non Keratinized is mostly associated with HPV, so having non keratinized SCC of the oropharynx has a positive prognostic benefit. It's also used in describing the tumor invasiveness, maybe as it applies to being HPV, as most are poorly differentiated are. The terms are also used in other conditions, areas of the body, even non cancer, being keratiinized or non Keratinized as Keratinization is one of the outermost cells replaced by keratin.

I'm not sure if I got this right, and surely it doesn't explain it all or that easily. I'll leave it also to someone with more knowledge to explain it.