What is the median?

Answer 1

In statistics: the median is the middle value in an ordered set of data. Where there is no single value in the centre of the set, the median is sometimes the mean of the two central values and sometimes one of the two central values (each of these two definitions can be more useful in different situations).

In normal English: when you put all the numbers in order from lowest to highest, the median is the number in the middle. If there is an even number of numbers, then either you take the middle two, add them, and divide by two to get the median, either you take one of the two near the middle.

In geometry: the median is the line segment from one vertex of a triangle to the midpoint of the opposite side of the triangle. This line divides the triangle into two equal areas. There are three medians in any given triangle, and all meet at the centroid.

In normal English: you draw a line from the corner to the middle of the other side. They all meet at the same place. You can do this three times for any triangle - three corners to their opposite sides.

There are several other uses for the word, which are more highly specialised and less known in general. See the related links for these, as well as fuller explanations of each.
the middle term in a numeric sequence or equation