Answer Description

The Public Cloud model provides infrastructure and services on-demand using infrastructure shared by all of the customers of the cloud provider. AWS, GCP and Azure are good examples of public cloud model. By using a Public Cloud model your client can migrate out of their on-premise data center and use the flexibility and ad-hoc subscription/billing model of a Public Cloud.

Wikipedia

Cloud computing is the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each of which is a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a pay-as-you-go model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users.