What does histogram mean in math?

A histogram is a graph, kind of like a cousin to the bar graph. A histogram has no spaces between it's bars, and the intervals on the horizontal axis are equal.

For example, if you take a survey and ask how many times you went to the movies each year, people wouldn't know the exact amount they went, so you would give them choices, such as 0-10, 11-20, 21-30, and 31+. So people wouldn't have to give the exact answer, just a rough estimate. And along the vertical axis you would have the number of people per bar depending on how many times they went to the movies.

I hope this helped