Predicate Logic Notation: What does a "dot" mean? What does a dot (.) mean in predicates?

$\forall a \in A. \exists d \in D. H(a,d)$

Especially, how is the above different to 

$ \exists d \in D. \forall a \in A. H(a,d)$

I've never seen this used in German lecture scripts.
The dot just means "such that"; it's often omitted.

The difference between the two formulas is the difference between "everybody has a mother" and "there is somebody who is everybody's mother."