Cloud Service Model: SaaS vs PaaS vs IaaS
A company decides to migrate its on-premises customer relationship management (CRM) software to the cloud. They want to avoid managing the underlying servers, operating systems, and runtime environments. They also want to focus only on configuring the CRM application to meet their business needs. Which cloud service model should they choose?
Quick Answer
The answer is Software as a Service (SaaS). This is the correct cloud service model because the company wants to avoid managing servers, operating systems, and runtime environments, focusing only on configuring the CRM application. In a SaaS model, the provider delivers a fully managed application over the internet, handling all underlying infrastructure, platform, and software maintenance, which perfectly aligns with the requirement to offload technical management. On the CompTIA A+ Core 1 220-1101 exam, this question tests your ability to differentiate cloud service models based on the level of control the customer retains; a common trap is confusing PaaS with SaaS when the scenario mentions application configuration but still implies platform management. Remember the memory tip: SaaS means you only bring your data and users—everything else is the provider’s job. For cloud service model selection, always ask who manages the stack: if the customer manages nothing below the application, it is SaaS.
⚠ Common exam trap
Candidates often confuse PaaS with SaaS, thinking PaaS also eliminates application management, but PaaS still requires the customer to develop and deploy the application code, whereas SaaS provides a ready-to-use application.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Software as a Service (SaaS)
(SaaS) is correct because the company wants to avoid managing servers, operating systems, and runtime environments, and only configure the CRM application. SaaS delivers a fully managed application over the internet, where the provider handles all underlying infrastructure, platform, and software maintenance, aligning perfectly with the requirement to focus solely on business configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Infrastructure as a Service (IaaS)
Why it's wrong here
IaaS delivers raw compute, storage and networking, leaving the customer to patch operating systems and runtime environments — exactly the burden the company wants removed. It appeals when full control over the stack is required, such as lift-and-shift migrations of legacy servers needing custom kernel or OS configurations.
When this WOULD be correct
A company needs to migrate its CRM to the cloud but requires full control over the operating system and middleware to install custom software or configure the runtime environment. They are willing to manage OS updates and patches but want to avoid physical hardware management.
- ✗
Platform as a Service (PaaS)
Why it's wrong here
PaaS provides runtime and middleware but the customer still deploys and configures the application and its dependencies. The scenario wants the provider to manage the CRM application itself, leaving only configuration. PaaS tempts because it removes server and OS management, yet stops short of application-level management.
When this WOULD be correct
A company wants to develop a custom CRM application using a cloud provider's development tools and database services, but does not want to manage the underlying servers or OS. They will handle the application code and configuration themselves.
- ✓
Software as a Service (SaaS)
Why this is correct
SaaS delivers a fully managed application where the provider handles servers, operating systems, and runtime environments. The company only configures the CRM to meet business needs, exactly matching the stem's requirement to avoid managing underlying infrastructure layers.
- ✗
Desktop as a Service (DaaS)
Why it's wrong here
DaaS delivers virtual desktop environments, not application hosting; the provider manages desktops while the customer still configures the CRM itself. It tempts when users need remote desktop access, but the scenario requires abstracting servers, operating systems and runtimes beneath a managed application platform.
When this WOULD be correct
DaaS would be correct if the question described a company needing to provide remote desktop access to employees, with the provider managing the virtual desktop infrastructure, and the company only managing applications and data on those desktops.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 220-1101 exam frequently reuses these exact scenarios with slightly different constraints.
✓Software as a Service (SaaS)Correct answer▾
Why this is correct
SaaS delivers a fully managed application where the provider handles servers, operating systems, and runtime environments. The company only configures the CRM to meet business needs, exactly matching the stem's requirement to avoid managing underlying infrastructure layers.
✗Infrastructure as a Service (IaaS)Wrong answer — click to see why▾
Why this is wrong here
IaaS provides virtualized servers, storage, and networking, but the customer still manages the operating system, runtime, and applications. The company wants to avoid managing servers and runtime, so IaaS does not meet their requirement.
★ When this WOULD be the correct answer
A company needs to migrate its CRM to the cloud but requires full control over the operating system and middleware to install custom software or configure the runtime environment. They are willing to manage OS updates and patches but want to avoid physical hardware management.
Why candidates choose this
Candidates may confuse IaaS with cloud migration in general, thinking that any cloud service involves moving infrastructure, or they may not fully understand the division of responsibilities between IaaS, PaaS, and SaaS.
✗Platform as a Service (PaaS)Wrong answer — click to see why▾
Why this is wrong here
PaaS provides a platform to develop and deploy applications but still requires managing the application code and configuration. The company wants to avoid managing servers, OS, and runtime, and only configure the CRM application, which is a SaaS characteristic.
★ When this WOULD be the correct answer
A company wants to develop a custom CRM application using a cloud provider's development tools and database services, but does not want to manage the underlying servers or OS. They will handle the application code and configuration themselves.
Why candidates choose this
Candidates may confuse PaaS with SaaS because both abstract infrastructure, but PaaS still requires application management, whereas SaaS provides a fully managed application.
✗Desktop as a Service (DaaS)Wrong answer — click to see why▾
Why this is wrong here
DaaS delivers virtual desktops, not CRM applications. The company needs a CRM application, not a desktop environment, so DaaS does not meet the requirement of configuring a CRM application without managing infrastructure.
★ When this WOULD be the correct answer
DaaS would be correct if the question described a company needing to provide remote desktop access to employees, with the provider managing the virtual desktop infrastructure, and the company only managing applications and data on those desktops.
Why candidates choose this
Candidates may confuse DaaS with SaaS because both are 'as-a-service' models that reduce management overhead, but DaaS focuses on desktop delivery rather than application delivery.
Analysis generated from the official 220-1101blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Same concept, more angles
1 more way this is tested on 220-1101
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A financial services company needs to migrate its customer transaction processing system to the cloud. Regulatory requirements mandate that all customer data must reside on servers physically located within the country’s borders and that the hardware must be dedicated solely to the company (no multi-tenancy at the hardware level). The company wants to retain the ability to scale resources on demand and manage the operating system and applications. Which cloud deployment model BEST meets these requirements?
medium- A.Public cloud
- ✓ B.Private cloud
- C.Hybrid cloud
- D.Community cloud
Why B: A private cloud is the only model that guarantees single-tenant, dedicated hardware while allowing the organization to manage the OS and applications and scale on demand. It satisfies the data-residency mandate (servers physically within national borders) and the no-multi-tenancy requirement, which public and community clouds cannot guarantee at the hardware level. Hybrid cloud could include a private component but does not by itself ensure all customer data stays in-country on dedicated hardware.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1101 exam.