How is Kolmogorov–Smirnov statistic non-constant?

Question

I'm reading about Kolmogorov–Smirnov test.

The Kolmogorov–Smirnov statistic is given by $$D_{n}=\sup _{x}\left|F_{n}(x)-F(x)\right|$$

It seems to me that $D_n$ is a constant for each $n$. Could you please elaborate on how $D_n$ is non constant?

Answer 1

@Cm7F7Bb confirmed my understanding is correct. I post it here to remove my question from unanswered list.

$F_n(x): \Omega \to \mathbb R$ is a random variable defined by $$F_n(x) (\omega) = \frac{1}{n} \sum_{i=1}^{n} \operatorname{I}_{[-\infty, x]}\left(X_{i}(\omega)\right)$$