What does the term $o(k^2)$ in $f(k)=k^2/2+o(k^2)$ mean ?
I have used the asymptotic notation only in context of algorithmic complexity.
With an analogy that, I am guessing it says $f(k)$ returns a value as great as $k^2/2$, and has another term that is at least of degree 2. But then it wouldn't be giving much info on $f(k)$, it could be of any order.
What i make out of $k^2/2+O(k)$ is $k^2$ is the term with the highest degree.
Thanks in advance.
EDIT: I would also appreciate sound references to the topic.