Shiva is inner meditative form of shree vishnu.
vishnu is one who is meditated by shiva in form of Rama!
Krishna is suprem god head and Bhagavati devi 'mahishasur mardini', (not devi parvati mata, sarasvati mata, lakshmi mata)
is adi yoga maya.
shivay nama om !
OM namaha shivaya!
Shiva is pure knowledge and father of all, mata parvati is mother of all.
shiva also can create destroy and nourish.
as well as shree vishnu also can do the things but all of them are with predefined powers and duties as per their mula guna.
Satva, raja, tama.