Relation of IaaS and PaaS

im trying to understand whats IaaS and PaaS and how they related to each other. There are a many picture like this In relation of this picture IaaS is a part of PaaS and PaaS cant stand alone, is that right ? I mean…i could use a PaaS in my company and „put“ this PaaS on my own infrastucture ? In this case i would manage the Virtualization Servers, Storage and Networking itself.
Can someone explain this ?