Is Oral History Valid?

In class we recently watched the Ken Burn's Docuseries The War. This series chronicled World War II from the perspective of four small towns in America. This film utilized no historians. All of the information used relied on oral history. This led to a discussion is oral history, history. I've came to the conclusion it is an aspect of history. This is one perspective on what happened. While it utilized no historical sources it utilized people who were actually there. Even if it had historians much of the documents on World War II are not available. Oral Histories cannot be discounted but they should not be the only source. But let's also remember what Voltaire said "History is a collection of agreed upon lies." This series just add to our story.