What are the main types of cloud computing?

The main types of cloud computing are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). These models differ in the level of abstraction they provide, from raw infrastructure to fully managed applications. Developers choose between them based on how much control they need over the underlying systems versus how much they want the cloud provider to handle.

IaaS gives access to virtualized computing resources like servers, storage, and networking. Providers such as AWS EC2, Azure Virtual Machines, or Google Compute Engine let developers rent infrastructure on demand. With IaaS, you manage the operating system, runtime, and applications, while the provider maintains physical hardware. This is useful for scenarios requiring custom configurations, like hosting legacy applications or running large-scale databases. For example, a developer might deploy a custom Linux VM on AWS EC2, install specific software, and handle scaling manually.

PaaS offers a platform for building and deploying applications without managing the underlying infrastructure. Services like Heroku, Google App Engine, or AWS Elastic Beanstalk abstract away servers, storage, and networking. Developers focus on writing code, while the platform handles deployment, scaling, and runtime environments. For instance, a team building a Node.js API could deploy it to Heroku, which automatically manages server provisioning, load balancing, and database integration. PaaS is ideal for web apps or microservices where speed and simplicity matter more than infrastructure control.

SaaS delivers fully functional applications over the internet, managed entirely by the provider. Examples include Gmail, Salesforce, or Slack. Users interact with these through a web browser or API, with no need to install or maintain software. Developers might integrate SaaS tools into their workflows—like using the Google Workspace API to automate document sharing. SaaS is best for end-user applications where maintenance and updates are handled by the provider, freeing developers from backend complexity. Each model serves distinct needs, balancing flexibility, ease of use, and administrative overhead.