what do the operator * exactly ?

Does somebody can explain me what the operators * and / do exactly?
for example
select '(1,1)'::point * '(2,2)':: point ;
gives
(0,4)

select '(1,1)'::point * '(3,3)'::point ;
gives
(0,6)

and what does the / operator ?
thanks for your response

MOLINET S.