The key differences between an oral history and an anecdote are verifiability, contextualisation, and multiplicity. The first issue is that a good oral history should contain information about who was being interviewed, and why. Anecdotes lack this, so it can be difficult to determine whether or not the person actually existed, let alone if they did what is claimed. For example, compare this oral history to an anecdote in a post by a redditor about the same battle. With one, I can look up, in the Navy List for May 1916 or elsewhere, whether or not Dannreuther was aboard the ship he says he was on. With the other, I have no way of verifying the anecdote. Secondly, there is little contextualisation to many anecdotes. With an oral history, we know who gave it, when they said it, and why. We know and understand their relationship to the events they were describing. With anecdotes, this information is again missing. Due to the anonymity of reddit, even with first-hand accounts, we have know idea how old the teller is, where they're from and so on. Going back to the Jutland example, an 18-year-old British seaman is going to have a very different experience of the battle from a 45-year-old German officer. Without knowing who's given the anecdote, we can't fully determine how useful the anecdote is for the topic - the 18 y/o Brit's account might be good for giving an idea of the conditions during the battle, but he's not going to have a good idea of what the strategic situation was. Finally, with oral histories, we frequently have multiple accounts of the same events or situations. Searching the Imperial War Museum Archives for oral histories on Jutland gives 82 results. Historians can weigh these against each other, weaving them together, using the given context, into a picture of the battle as it actually happened. An anecdote is just a single data-point. It gives one perspective of the event, and brooks no discussion of anyone else's perspective. However, different people can, and do, give very different accounts of the same event - history must include all perspectives, otherwise we can never get a true picture of events. For the Mod team's view on this, see this rules roundtable.

While /u/thefourthmaninaboat makes good points about oral history, he mainly tied it to western methods of practicing history. In the west, most cultures have a written language, and that is the form their histories take. In other cultures, that's not the case.

In New Zealand, the Māori had no written language until the arrival of European missionaries who taught them to use our alphabet, and turned the spoken language into a written one. Prior to this, oral history was the only form of recounting the history of the iwi(tribes) and the people as a whole.

This obviously intersects with other aspects of Māori culture, like the fact that they didn't have the same concept of time as Europeans. While the west measures dates from the birth of Jesus, and referred to events as occurring in 1798, or 1866, Māori tracked events by the relation to their whakapapa(genealogy). So the arrival of Captain Cook in 1769 might have been referred to by mid-19th century Māori as occurring in the time of their grandfathers, while earlier events would be attached to earlier ancestors.

In this regard, oral histories appear quite vague and unreliable when viewed through a western lens that values documentation, hard fact, and ordered chronologies. But oral histories have been shown to be very accurate. Judith Binney has an example of this in a book chapter titled 'Encounters Across Time'(it appears in the book Telling Stories: Indigenous History and Memory in Australia and New Zealand, eds. Bain Attwood and Fiona Magowan, Wellington, 2001). I can't remember the exact details, but Binney discovered some old photographs of Māori, took them to the region where they had lived, and local Māori who had no copies of the photographs were able to point out who these people were and tell their stories, despite them having been dead for decades.

Another article about oral history is 'Māori Oral Narratives', also by Binney. In that she writes that oral histories have a lifespan many times that of writte histories, which are constantly revised. But in the same way, details are changed in oral histories which refresh them and keep the history alive in the culture of the people. She also gives several examples of how oral history is recorded among Māori, and probably the most easily understood one for westerners is waiata or song. Because songs have a repetitive rhythm, like poetry, they're easily remembered. Think nursery rhymes, hymns, pop songs, and those silly songs you sang as children. Many of them will stick in your head thought you made no conscious effort to learn them. In the same way, a song recounting the oral history can be easily remembered and taught to new generations, ensuring the history will endure through time.

I'm skeptical that we'll get many questions on it related to the theme, but it's worth having "oral history" as a theme topic in my view if only to discuss the historiographical merits of oral history precisely because of those objections to it. Much of the historiographical debate within early Islam continues to be related to whether or not we can use "traditional" sources, that is, sources that were written down based on compilations of oral traditions that were passed down over the course of a couple centuries. As with anecdote in the sub, there are historians who say, "No, these sources are fundamentally compromised and we must look elsewhere."