This is the 7685th most frequent Portuguese word.
pequena
Small; little.
Here, 'pequena' is used as an adjective describing the noun 'casa', indicating its size relative to other houses.
Ela tem uma casa pequena no campo.
She has a small house in the countryside.
In this sentence, 'pequena' describes the noun 'diferença', signifying that it is minor or not substantial.
A diferença entre os dois produtos é pequena.
The difference between the two products is small.
'Pequena' is used here to modify 'coleção', suggesting that the size or extent of the collection is not large.