Let me give you an example taken from what I've been doing the last two days, working on a new paper. My "research" for this paper has consisted of me locating sources and taking notes on them. As I do this I will come up with an interpretation of how they fit into a historical narrative and what it means about the historical events in question, at both large and small scales of "history." The sources are all from archives of different sorts, and sometimes are pieces from secondary sources as well. Every one of these sources has been looked at by other human beings — at the very least, when they were created, but more recently when they were entered into the archive's holdings or database. But as far as I can tell no other human being has tried to compile a historical narrative out of these disparate sources, which are mixed in with large numbers of other sources on different topics. Looking at any one source, it's essentially impossible to see the larger narrative they represent — my job is to figure that out.

Ultimately, the paper I am writing will turn the hundred or so sources I've been looking at into a written narrative that will tell a story about something that happened (in this case, a US governmental policy decision — sorry for being coy, but I don't want to spoil the details at the moment), and explain both how to understand it in the context of things already known, as well as showing how it gives understanding that was previously unknown. That's the "output" in the end.

In my work, I generally am not trying to apply some brand-new framework to my understanding of the past; I prefer doing work that tells new stories, as opposed to reinterpreting older ones, but that's just a personal preference. I associate people talking about "cutting edge" with applying new theories to old stories to make new stories (this often involves looking at different/new sources, too). But my work is "cutting edge" in that no other historian has tried to tell the story I'm writing, and it will (I think) significantly advance the understanding of the historical community surrounding the broader topic it belongs to. It's definitely "cutting edge" to anyone outside of my academic community; you won't find this story on Wikipedia, or in the newspapers, or in any popular historical sources. It does represent the vanguard of historical scholarship on this particular topic (for better or worse).

It's very rare that historians find truly "new" sources that are not inside archives. We generally rely on archivists to facilitate that sort of thing. It's not unheard of, though. But it's much rarer. Archivists sometimes get annoyed about historians "discovering" sources that an archivist has already cataloged. But the job of the archivist is very different than that of the historian; an archivist is about collecting and preserving primarily, whereas the historian is about interpreting and producing narrative. So when a historian "discovers" something, they are really saying, "I introduced a source into the narrative where it had been previously overlooked or ignored." Or, "I saw the relevance of a particular source to a broader historical argument or conversation that nobody else has published on," to be more specific.

For example, I "discovered" a photograph of something that I don't think anyone else has given much attention to — but I "discovered" it in a report that has been on the internet for a long time. My "discovery" here is less about finding the actual photograph as it is being able to understand the meaning of what is in the photograph, which elevates its importance dramatically. (Once you know what the photograph is of, it would be trivial for you too to "find it" — the difference is that you would never have thought to look for it, or understood it, before I told you what it really was.) This is a form of historical discovery in my mind.

Sometimes historians use new tools and techniques (e.g., data analysis, chemical analysis, etc.) for doing history, and one might call that "cutting edge," but that is also exceedingly rare, at least for historians whose sources are primarily document-based (as opposed to the places where archaeology and history overlap).

In addition to the traditional approaches to history (i.e. "cutting edge" in the sense of new theoretical/methodological approaches), there are many interdisciplinary projects that involve various technologies to allow us to gather more information from known sources, or to access information from newly discovered sources by less destructive means.

For example, about a decade ago a scholar requested that the British Museum subject two patches on John White's map of Virginia to infrared reflectography, optical microscopy, X-Ray fluorescence (XRF), and Raman spectroscopy to see what was underneath. Under one, they found a drawing of a fort located in Albermarle Sound, which archaeologists and historians have used as a basis for new excavations to find remnants of the Lost Colony, with some success. These techniques are being used on a wide variety of manuscripts, especially palimpsets, to allow scholars to "see" information that we previously could not access.

Another interesting project being carried out by a research group affiliated with the Bodeleian Library is the transcription of unopened letters found in a cask that had been sitting in the Hague. These undelivered letters date to the 17th century and represent a potentially rich source of information about ordinary people, but opening them to access that information could destroy much of their value as material objects. So historians have collaborated with MIT to figure out a way to read them without destroying their seals or otherwise sacrificing the material information. http://emlo-portal.bodleian.ox.ac.uk/collections/?catalogue=brienne-collection

Still other "cutting edge" projects in the history of science and technology are using manuscript sources to try to reverse-engineer experiments or figure out the actual techniques and ingredients used by medieval/early modern craftsmen. A particular example of this is Pamela Smith's Making and Knowing Project. https://www.makingandknowing.org/