This is the 11967th most frequent Polish word.
kwiat
Flower.
Here, 'kwiat' is used as a singular noun meaning 'flower' to describe an attribute.
Kwiat jest piękny.
The flower is beautiful.
In this sentence, 'kwiatów' is the genitive plural form of 'kwiat', used to denote a quantity of flowers.
Dostałem bukiet kwiatów na urodziny.
I received a bouquet of flowers for my birthday.
Again, 'kwiatów' is used in the genitive plural form, indicating a variety of flowers in the garden.