IasS vs PasS vs SaaS

Question 1

What is Infrastructure as a service (IaaS)?

Answer 1

• Instant computing infrastructure, provisioned and managed over the internet.
• Aims to give you the most control over the provided hardware that runs your application
• E.g. virtual machines (VMs), storage, and operating systems.
  You rent hardware instead of buying

Question 2

Explain common laaS use cases

Answer 2

• Migrating workloads: Managed similar to on-prem infrastructure & provides easy migration path.
• Test and development: Teams can quickly set-up & dispose test/dev environments with fast & economical scaling.

Question 3

What is Platform as a service (PaaS)?

Answer 3

• Provides an environment for building, testing, and deploying software applications
• Aims to help creating an application quickly without managing the underlying infrastructure.
• E.g. for a web app / Azure SQL databases you don’t need to install an operating system, web server, or even system updates.

Question 4

What is Software as a service (SaaS)?

Answer 4

• Software that is centrally hosted and managed for the end customer.
• E.g. Office 365, Skype, and Dynamics CRM Online.

Question 5

Explain Management Resposabilities amongst services

Answer 5

• IaaS: user is responsible for managing the operating systems, data, and applications.
• PaaS: user is responsible for the applications and data they run and store.
• SaaS: user just uses the software.