Binomial Distribution

[RobGillespie]

For this program I'm supposed to write a code that displays a binomial distribution as a simple text bar graph something like this:

Number: 4
1 @
4 @@@@
6 @@@@@@
4 @@@@
1 @

I'm supposed to allow the user to select the number of elements in the distribution. The above example were if 4 was entered.
This is what it would look like if 5 was entered:

Number: 5
1 @
5 @@@@@
10 @@@@@@@@@@
10 @@@@@@@@@@
5 @@@@@
1 @

Then it says that the amount of '@' symbols can be found by calling Combinations(n,k), where n is the number of elements, and k is the row number starting with 0.

First off, I don't even know what binomial distribution is. It doesn't even sound familiar to me. I'm a proficient math student currently taking Calculus II and this topic has never crossed my path in any of the mathematics that I've taken. I need to use a nested for loop for this code, that's all I really know about it. Can anyone explain to me what binomial distribution is?

[giblit]

what binomial distribution is?

You probably wouldn't have learned it unless you have taken a probability class.
http://en.wikipedia.org/wiki/Binomial_distribution
https://www.khanacademy.org/math/probability/random-variables-topic/binomial_distribution/v/binomial-distribution-1