# What do these mathematical symbols mean?

I don't have a substantial background in Maths, but I do enjoy doing little projects with computers that often require a better Mathematical knowledge than I possess. So at the moment I'm reading up on Principal Component Analysis in order to later understand how facial recognition works.

I came across a formula I tried pasting it but I can't figure out how to add symbols with MathJax/Latex. Basically a Sigma symbol with super positioned n and a sub position i=1. The question is, does this just mean a loop, so sum all the elements from i=1 to n? I found an explanation for the Sigma symbol but couldn't find anything that explained the n and the i=1, everything just assumes you know becuase you've been studying Algebra and Calculus for years, which I haven't.

This is summation notation. $\sum_{i = 1}^n f(i)$ means $f(1) + f(2) + \dots + f(n)$. Example $\sum_{i = 1}^4 i^2 = 1 + 4 + 9 + 16$.