"Limiting" and "approximate" are not necessarily the same thing. *Limiting* is specifically a distribution coming from some asymptotic result, so if you take $Y=t(\underline{X})$ and let's say that $\mu_Y= \theta(1-4/n)$ and $\sigma_Y=(2+2/n)/\sqrt{n}$ and you can show that $\lim_{n\to\infty}\frac{Y-\theta}{\sqrt{n}}\sim N(0,2^2)$, you can say "the limiting distribution of $\sqrt{n}(Y-\theta)$ is $N(0,2^2)$", and you might from that obtain an approximation for the distribution of $Y$ at $n=8$, say but for $n=8$ the distribution of $Y$ may be better approximated by a normal with $\mu=\frac{\theta}{2}$ and $\sigma^2=40\frac{1}{2}$ than what you'd get from substituting $n$ into the limit calculation.

So "are they the same" in general depends on what approximation you're using. 

If you used a limit result for a standardized $Y$ to obtain your approximation for for the distribution of $Y$ at some $n$ (which it looks like you did) then you might *loosely*(!) say that you're using the limiting distribution, though really it's an approximation obtained from the limiting distribution.