What does this mathematical notation mean? Please excuse this simple question, but I cannot seem to find an answer. I'm not very experienced with math, but I keep seeing a notation that I would like explained. The notation I am referring too generally is one variable m floating over another variable n enclosed in paraentheses. You can see an example in the first equation here.
What does this mean? Thanks in advance for the help.

This is called the binomial coefficent, often read "n choose m", since it provides a way of computing the number of ways to choose $m$ items from a collection of $n$ items, provided the order or arrangement of those items doesn't matter.
To compute the binomial coefficient: $\displaystyle \binom{n}{m}$, you can use the factorial formula: $$\binom{n}{m} = \binom{n}{n-m}=\frac{n!}{m!(n-m)!}$$
