SaaS supports multiple users and provides a shared data model through which model
Answers
Infrastructure as Service is a cloud computing service model in which hardware is virtualized in cloud.
This model the service vendor owns the equipment i.e. servers, storage, network infrastructure and so forth.
The developer interacts with this model to create virtual private servers, virtual private storage, virtual private networks and then populates these virtual systems with the applications and services it needs to complete its solution.
SaaS supports multiple users and provides a shared data model through Multi-tenancy model.
The alternative of the software virtualization in case of the individual instances exists but is not common.
The Multi-tenancy model refers to the software architecture and can serve multiple tenants. The tenant is the group of the users who can share the common access with various privileges.