LearnViz CompSci
Home / Learn / Distributed Systems & Cloud / IaaS, PaaS, SaaS

Beginner Topic 11 of 51 Distributed Systems & Cloud

IaaS, PaaS, SaaS

Service tiers from raw infrastructure to finished software.

How it works

Cloud service models differ by how much the provider manages. Infrastructure as a service gives virtual machines, storage and networks, with the customer managing operating systems, middleware and applications, as with EC2 and Compute Engine. Platform as a service provides a managed runtime and tooling so developers deploy code without handling servers, as with Heroku, App Engine and Elastic Beanstalk. Software as a service delivers complete applications over the web, such as Gmail, Salesforce and Slack. Functions as a service and containers as a service sit between.

Where it is used

Teams choose IaaS for control and legacy migration, PaaS for fast development and SaaS for ready-made capabilities, often combining all three.

Common pitfall

Higher levels give less control and customization and can lock you in, while lower levels demand more operations work and security responsibility. Responsibility boundaries are often misunderstood, causing gaps such as unpatched virtual machines. Cost models differ. Match the model to team skills and requirements, and evaluate portability.

Where it fits in the course

IaaS, PaaS, SaaS is topic 11 of 51 in Distributed Systems & Cloud, rated Beginner. It follows Cloud Computing. The next topic is Virtual Machines in Cloud.

Practice and explore

How to study this topic

  1. Read the explanation above and restate the definition in your own words.
  2. Open the interactive lesson and answer its mini quiz.
  3. Read the common pitfall, then write a short example that avoids it.
  4. Check your understanding in the Distributed Systems & Cloud quiz, and revisit the topic if you miss a question.

Frequently asked questions

What is IaaS, PaaS, SaaS?
Service tiers from raw infrastructure to finished software. It belongs to Distributed Systems & Cloud and is a beginner-level topic.
Where do people use IaaS, PaaS, SaaS?
Teams choose IaaS for control and legacy migration, PaaS for fast development and SaaS for ready-made capabilities, often combining all three.
What is the most common mistake with IaaS, PaaS, SaaS?
Higher levels give less control and customization and can lock you in, while lower levels demand more operations work and security responsibility.
What should I learn before this topic?
Start with Cloud Computing, the topic just before it in Distributed Systems & Cloud.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Distributed Systems & Cloud quiz.
Is IaaS, PaaS, SaaS hard to learn?
It is a Beginner topic, so it works as an entry point. If the terms are new, read the explanation twice and try the visualizer before the quiz.
How long does it take to learn IaaS, PaaS, SaaS?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to IaaS, PaaS, SaaS?
Cloud Computing, Virtual Machines in Cloud, Message Queues are closely connected. The full list is in the related topics section of this page.
What should I study after IaaS, PaaS, SaaS?
Continue with Virtual Machines in Cloud, the next topic in Distributed Systems & Cloud.

Related topics