I thought they were biscuits?
In the UK "cookie" means a specific type of sweet baked product, roughly round and fairly flat, often 3-4 inches across and a bit under half an inch thick. If the consistency is right, they're slightly hard on the surface, and softer inside. They often contain things like chocolate chips, bits of fruit, or other flavourings. I think these are called cookies in the US as well. "Biscuit" over here would usually refer to something smaller and crisper than a cookie.
On the
Wikipedia page, the photo at the top shows a British cookie; the middle two photos show things that we would call biscuits.
