IaaS: work with infrastructure
Infrastructure as a Service gives you building blocks such as virtual machines, storage and networking. With a virtual server, your team typically handles the guest operating system and application configuration.
Choose it when control over the operating system or runtime matters. Include patching, monitoring and backups in the work estimate rather than counting only the time needed to launch a server.
PaaS: focus on the application
Platform as a Service provides more of the application environment. You bring application code and configuration while the service manages more of the underlying platform. The exact boundary varies by product.
A development team deploying a web application may prefer a managed platform to reduce operating-system work. It must still understand access, application security, scaling settings and service limits.
SaaS: use the finished application
Software as a Service provides an application you use, often through a browser. A team using a hosted email or collaboration product generally does not operate its underlying servers.
You still manage users, sharing settings and the information you place in the application. More managed does not mean there are no customer responsibilities.
Try it yourself
Compare a virtual server, a managed application platform and a hosted email application. For each, list who updates the operating system, deploys application code and grants user access.
A common question
Is one model always better?
No. Choose according to the control you need, your operating skills and the work you want the provider to manage.
References & video notes
An original CloudFolks companion guide to the topic. Older video interfaces and offers may differ from current services. Use the current documentation for implementation details.
Keep learning
- Public, private and hybrid cloud explained
- AWS Regions and Availability Zones explained
- Getting comfortable with the AWS Management Console