Cloud computing is conventionally split into three service models: IaaS (Infrastructure as a Service), PaaS (Platform as a Service), and SaaS (Software as a Service). They differ in how much of the stack the provider manages versus how much the customer manages. Salesforce sits primarily in SaaS — customers consume finished applications (Sales Cloud, Service Cloud) over the browser — and also offers a PaaS layer called Lightning Platform (formerly Force.com) for building custom apps on Salesforce infrastructure.
The three models, layered
Customer manages | IaaS | PaaS | SaaS
---------------------------|--------|--------|------
Application | You | You | Provider
Data | You | You | You*
Runtime / Middleware | You | Provider | Provider
Operating System | You | Provider | Provider
Virtualization, Servers,
Storage, Networking | Provider | Provider | ProviderThe lower in the stack you go, the more flexibility you get — and the more responsibility you keep.
IaaS — raw infrastructure
Examples: AWS EC2, Azure Virtual Machines, Google Compute Engine. You rent virtual servers, storage, and networking. You install your OS, patch it, deploy your applications, manage runtimes. Maximum flexibility, maximum ops burden.
PaaS — platform to build on
Examples: AWS Elastic Beanstalk, Heroku, Google App Engine, Salesforce Lightning Platform / Force.com. You write code; the provider handles servers, runtime, scaling, OS patches. You focus on the application; you don’t manage compute or storage directly.
Salesforce’s Lightning Platform is PaaS — developers build custom objects, Apex code, Lightning Web Components, flows. They don’t manage the database, the JVM, or the web servers.
SaaS — finished application
Examples: Gmail, Office 365, Salesforce Sales Cloud / Service Cloud / Marketing Cloud. You sign up, log in, configure to taste, and use. The provider runs everything — application code, infrastructure, the works. You’re a tenant on the vendor’s app.
Where Salesforce fits — both at once
Most of Salesforce’s flagship products are SaaS:
- Sales Cloud — sales force automation.
- Service Cloud — customer support.
- Marketing Cloud — marketing automation.
- Experience Cloud — community/portal sites.
The platform layer underneath — where you build custom apps — is PaaS:
- Lightning Platform (formerly Force.com).
- Heroku (which Salesforce acquired) — PaaS for Node.js, Ruby, Java, Python, and others.
This dual nature is why interviewers ask the question — you should know Salesforce is both SaaS and PaaS depending on which product line you’re talking about, and it does not offer IaaS.
Verified against: Salesforce Help — Salesforce Editions and Products and Trailhead — Salesforce Platform Basics. Last reviewed 2026-05-17.