An objective historian is like a teacher who looks at different sources to learn about the past and tries to tell us what happened in the most fair way possible. It's just like when you and your friends disagree about something and you ask someone who wasn't there to explain what happened. An objective historian tries to be like that someone and explain what happened in a way that's fair to everyone.
For example, let's say you and your friends were playing a game yesterday, and today you're arguing about who won. An objective historian would listen to everyone's stories, look at pictures or videos of the game, and try to figure out what really happened. They wouldn't just believe one person without checking the facts first.
Historians also try to understand why certain things happened in the past. They look at the time period, culture, and society to explain why people acted a certain way. For instance, why did people in the past treat certain groups of people unfairly? Historians try to give us an idea of what life was like during those times and why people acted the way they did.
Overall, an objective historian is someone who tries to give us an honest and fair understanding of what happened in the past. They don't just believe one side of the story, but try to research all the facts and tell us what really happened.