Little $o$ notation is a form of [[Asymptotic Notation]] that describes a *strict upper bound* of growth of a given function $f$. For a given function $f(x)$, we can denote that as $x\to \infty$ that the asymptotic behavior of $f$ will be *slower* than some other function $g(x)$ by denoting: $\huge f(x) \in o(g(x)) $ More explicitly, $\huge \begin{align} f(x) \in o(g(x)) \implies \lim_{ x \to \infty } \frac{f(x)}{g(x)} =0 \end{align}$