How many types of cloud computing service are there

IaaS (Infrastructure as Service):

IaaS provides users with access to computing resources such as networking, processing power, and data storage capacity. It is used by businesses and organizations so that they do not need to install hardware in their office, it provides flexibility, reliability and scalability to the organizations as per their requirement.

PaaS (Platform as a Service):

PaaS provides a platform for developers and programmers to create, test and deploy web applications. All servers, storage and networking are managed by the enterprise or third-party provider while the web application can be managed by the developer himself. Examples are Google App Engine, Salesforce, Joyent, Azure etc.

SaaS (Software as a Service):

It is a specialized cloud computing service that includes features of both IaaS and PaaS. Through this online software application can be hosted which can be used by the users on the basis of monthly subscription. A SaaS app is a type of web application or mobile app that users can access through a web browser.