Okay, so Harlan Ellison was a man who wrote stories, like someone who tells you a really cool bedtime story. But his stories were for grown-ups, not for little kids like you. He wrote lots of different kinds of stories, like scary ones, funny ones, and even ones that made people think really hard.
Harlan was also a really interesting person, and some people thought he was kind of strange. He used big words and had strong opinions about things. He was known for being a bit grumpy sometimes, but he was also really passionate about what he believed in.
Lots of people really liked Harlan's stories, and he won lots of awards for his writing. But some people didn't like him so much, because he could be kind of mean to them if they disagreed with him.
Overall, Harlan Ellison was a really talented writer who wrote stories that people loved. But he was also a complicated person who some people didn't always agree with.