Confusion about des and 'some' or 'several'

In lesson plan 2 it mentions des when used for 'some' or 'several' and a plural noun. It is then mentioned a little later for 'of' or 'of the' and any plural noun. An example for the first usage is 'Some flowers' which is 'Des fleurs'. However it then mentions du, de la, d', de l' and des can be used for 'some' and 'several'. An example given is 'Some cheese' which is 'Du fromage'. This confuses me! Why 'des' in the first case but 'du' in the second?

"du" is used to describe "a piece of a piece". If you have a big whole piece of cheese in your hand and you break a piece off you have "du fromage", some cheese broken of a big piece. "du" is used with the masculine noun, whereas "des" is used with any plural noun. "Des" can mean "some", "several" and "of" or "of the". You might like to listen to lesson 4.2 of the Interactive Audio Course, which covers the use of different articles. I hope that helps.

Yep, I understand, thank you!