This is the 970th most frequent Italian word.
vasta
Wide; vast; extensive.
Here, 'vasta' is used as an adjective describing the noun 'area', indicating its broadness or extensiveness.
Questa è una vasta area di conoscenza.
This is a vast area of knowledge.
In this case, 'vasta' qualifies 'scelta', expressing the abundance or variety of choices.
Abbiamo una vasta scelta di opzioni.
We have a wide range of options.
Here, 'vasta' is again an adjective modifying 'collezione', emphasizing its great size or richness.