The types of cloud computing available are originally three. However, new demands and opportunities have led to new types gaining ground, as follows:
In the public model (Public Cloud), the resources used by users are shared.
In it, the service provider makes resources available, such as virtual machines (VMs), applications or storage, to the general public over the Internet. Public cloud services can be free or offered on a “pay-per-use” model.
The public cloud is characterized by being a virtualized environment, that is, designed by virtual machines on a set of servers (cluster). Despite the sharing of resources by users, each tenant in the public cloud has their data isolated from the others and both their privileges and access to them are individualized by user and password .
Another characteristic of the public cloud is the reliance on the use of high bandwidth to transmit data quickly to a large number of users. As for storage, it is usually redundant, with data replication in different locations, which results in high resilience and security.