What exactly is a research paper? I have heard a lot about people doing research and writing papers about it, but I’m not sure in which cases the papers would be called a research paper.

Here are a few hypothetical example cases I could think of:


A found a technique to increase clock speed of microprocessors
B did research on life on a historical person by visiting people and places related to him. She/He found new information and She/he was first to successfully join the bits of information about that persons life.
C researched about a writer. She/He did not find anything new, She/he just collected various information from different sources and put it together.
D used sources like internet and books to show how technology X is very essential for doing Y. Although this may be obvious to some, no one has written about it before.


Assuming each of them writes about their work, who would write a research paper? When is something called a research paper?

My Internet research so far was not successful, as I did not understand the concept of a research paper and everyone said something different.
A research paper is a paper that contributes some new knowledge to your field. That is, if you do some work (research) that adds to the body of knowledge in your field, and you write up the methods and results of your research in a paper, this can be called a research paper.

So in your example cases:


If A's technique is an important bit of knowledge that will move the field forward, then a paper describing it is a research paper. If it's a straightforward application of things that are already known, or a hack that's not going to move the field forward, it's probably not going to become a research paper.
D's work would not be considered research, if it's obvious to those in the field.
I don't know enough about standards in history to judge what's considered a contribution to the field, so I can't comment on B or C.