What Is Cloud Computing? A Beginner’s Guide to IaaS, SaaS, PaaS and Market Trends

Concept Overview

Cloud computing is the centralized deployment and reallocation of computer hardware, systems, networks and application software to maximize resource utilization.

The original goal was to manage three types of resources: compute, network and storage.

IaaS (Infrastructure as a Service)

IaaS offers customers basic computing resources such as virtual machines, CPU, memory, firewalls and network bandwidth. Pricing can be based on CPU‑hours, storage per GB, bandwidth usage, or other consumption metrics.

Early pioneers include Amazon, Rackspace, Gogrid and Joyent.

SaaS (Software as a Service)

SaaS delivers applications that run in the cloud, allowing users to access them from any device without managing servers, operating systems or storage.

Typical examples are Google Apps, Salesforce, Microsoft Dynamics, Dropbox and OneDrive.

PaaS (Platform as a Service)

PaaS supports the entire software lifecycle for developers, testers, deployers and administrators. Popular services include Google App Engine, Microsoft Azure and Amazon Elastic Beanstalk.

Cloud Deployment Models

Public Cloud

Public clouds are offered by commercial providers such as Amazon, Google and Microsoft. They provide low cost, high scalability, but users have limited control over underlying resources.

Private Cloud

Private clouds are dedicated to a single organization, either on‑premise or off‑premise, offering greater control and security. Main providers include IBM and Amazon.

Hybrid Cloud

Hybrid cloud combines public and private clouds, allowing non‑critical workloads to run in the public cloud while keeping critical applications and data in a private environment. Major providers are IBM and Microsoft.

Market Overview

The 2018 Q3 cloud industry report shows that spending is increasingly concentrated among a few giants—Amazon, Microsoft and Alibaba—who together hold over 55% of the market, a share projected to reach 84% by 2019.

Gartner’s 2018 IaaS Magic Quadrant listed only six vendors, down from fifteen the previous year, indicating a rapid consolidation of the market.

AWS IoT Core – device‑cloud connectivity

Amazon FreeRTOS – IoT OS for micro‑controllers

AWS Greengrass – local compute, messaging and device sync

AWS IoT Analytics – analytics for IoT data

AWS IoT Device Defender – security management for IoT devices

Conclusion

In China, cloud adoption has moved from a cautious observation phase to deep integration with vertical industries. While policy support and customer acceptance favor migration, small and medium enterprises face significant challenges competing with dominant providers.