SaaS (Software as a Service)
SaaS is a cloud computing model where software applications are delivered over the internet and managed entirely by the service provider.
What is SaaS?
Software as a Service (SaaS) is a cloud service model in which applications are hosted, maintained, and updated by a provider and accessed by users through a web browser or thin client. Users do not install or manage the underlying infrastructure, operating systems, or application updates.
Why SaaS matters
SaaS is widely adopted because it:
- Reduces infrastructure and maintenance costs
- Enables rapid deployment and scalability
- Simplifies updates and patch management
- Supports remote and hybrid work
- Provides predictable subscription-based pricing
Most modern business applications are now delivered as SaaS.
Common SaaS use cases
SaaS is commonly used for:
- Email and collaboration platforms
- Customer relationship management (CRM)
- Human resources and payroll systems
- File storage and document management
- Security and identity services
SaaS spans both productivity and mission-critical workloads.
SaaS vs PaaS vs IaaS
| Model | You manage | Provider manages |
|---|---|---|
| IaaS | OS, runtime, apps | Hardware, virtualization |
| PaaS | Application code | Infrastructure, OS, runtime |
| SaaS | Configuration & data | Entire stack |
SaaS offers the least operational control but the highest convenience.
SaaS and security considerations
In SaaS environments:
- Providers secure the application platform
- Customers are responsible for user access, configuration, and data governance
- Misconfigurations and identity compromise are leading risks
Strong identity controls are essential for SaaS security.
SaaS and Zero Trust
SaaS applications align well with Zero Trust principles:
- Identity-based access replaces network trust
- MFA and conditional access are critical
- Continuous monitoring of user behavior
- Least-privilege permissions and role management
SaaS security is primarily an identity problem, not a network one.
SaaS benefits and trade-offs
Benefits
- Fast deployment
- Minimal IT maintenance
- Automatic updates
- Accessibility from anywhere
Trade-offs
- Limited customization
- Vendor dependency
- Data residency concerns
- Integration and portability challenges
Common misconceptions
- "SaaS providers handle all security"
- "SaaS apps don't need backups"
- "SaaS is only for small businesses"
- "All SaaS apps are equally secure"