Harry Potter : Blood Purity???

Question: Harry Potter : Blood Purity!?!?!?

Can you tell me why Harry's and Ginny's children are considered as half bloods!?!?!? They should be pure bloods , since Harry is half blood and Ginny is a pure blood !.!.!.!.
I thought they were pure bloods , until i read on harry potter wiki that they are half bloods !.!.!.
Here's the link :
http://harrypotter!.wikia!.com/wiki/Half-b!.!.!.
(see Two Magical Parents, Known Muggle Ancestry)

Thank you XDWww@QuestionHome@Com

Best Answer - Chosen by Asker:

They are half-bloods because there are muggle blood in them (Harry's Mother was Muggleborn)!.
Its not a matter of whether your parents are both wizards, but rather about whether there are any mubble-blood in you!
So yes, Albus,James and Lilly would be half-blood because of the Muggle-blood running through them!Www@QuestionHome@Com

because harry's mother was muggle born so there is muggle blood in their ancestry Www@QuestionHome@Com

Well, since Harry is a half blood, I suppose strictly speaking his children should be quarter bloods!.Www@QuestionHome@Com