Virtual machine, networking, load balancers, firewall, anything that is a physical device that is in your network but we are using virtually on the cloud.
This is an abstraction over IaaS. Example: We upload a code repository and the cloud provider runs it. We don’t choose the infrastructure here.
Example: Office 365, Active directory
Abstraction over PaaS. We interact with a pre existing application on the cloud.
The responsibility related to security the customer and cloud provider have to share.
Physical security is always with the cloud provider. Information and data, devices, accounts and identifiers are always customer responsibilities. Responsibilities are shared by service type, for example: In IaaS OS will be your responsibility but not so for PaaS and SaaS.