I know that when I have a discrete time signal, let's say:
$$f(t_n),\;t_n=\dfrac{n}{F_s}$$
The definition of the DTFT is given by:
$$F_n(\omega)=\sum_{n=0}^{N-1}f(t_n)\cdot e^{-i\omega_nt_n}$$
Now, my question is regarding $\omega_n$.
I know the frequencies will be discret because we can't measure lower frequencies than the difference between $t(n+1)$ and $t(n)$.
However, I am not clear how exactly this works, and how can one determine the "frequency vector". I am not sure I got the expression for $t(n)$ correct.
I am sorry this question isn't 100% clear, it's because I'm trying to make heads and tails from this definition and articles online are not very clear.
Thank you.