Most of my searches either end up explaining any of the above words in terms of the other four, or explaining the concept in simple words in such a way that makes it difficult to see the difference between them.
A simple google search took me to medicinenet.com -
pathology - "that branch of medicine which treats of the essential nature of disease."
etiology - "The study of causes, as in the causes of a disease."
Pathogenesis: "The development of a disease and the chain of events leading to that disease."
So I decided to try wikipedia as, I felt, all definitions will necessarily fail to actually explain the differences between them as the differences are pretty nuanced.
But wikipedia articles on these terms were either very detailed or very general, in the sense that although I understood what they were saying in any particular article, I still couldn't figure out how the rest of the terms were referring to something different. All seemed to mean - understanding why and how diseases work/spread and how to control them.
The only term I understood distinctly here was epidemiology, which means studying the occurrence of diseases in a given population (thus putting a geographical limitation).
I guess I'm looking more for an explanation which draws a parallel to convey the message. Definitions won't work.
For ex, if someone were to ask me the difference between environment, habitat, ecotone and niche, I would try something along the lines of -
Environment = library
Habitat = different sections (like literature, reference, philosophy etc)
Ecotone = gate of library
Niche = the place a particular student occupies in that library through his interaction with other students etc