What Is Cloud Computing? A Beginner’s Guide to Models, Services, and Market Trends

Concept and Origin

In 2006, the term “cloud computing” was first introduced at a search‑engine conference, and in recent years it has been commercialized by companies such as Amazon, Alibaba, and Microsoft.

Simply put, cloud computing centralizes the deployment and reallocation of hardware, system, network, and application resources to maximize utilization. The primary resources managed are compute, network, and storage.

Service Models

IaaS (Infrastructure as a Service)

IaaS offers fundamental computing resources such as virtual machines, CPUs, memory, firewalls, and network bandwidth. Pricing can be based on CPU‑hour, storage‑GB‑hour, 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 underlying infrastructure. Common examples are Google Workspace, Salesforce, Microsoft Dynamics, Dropbox, and OneDrive.

PaaS (Platform as a Service)

PaaS provides a complete development and deployment environment for developers, testers, and administrators. Popular platforms include Google App Engine, Microsoft Azure, and Amazon Elastic Beanstalk.

Deployment Models

Public Cloud

Public clouds are offered to the general public and are owned, managed, and operated by commercial, academic, or government entities. Advantages include low cost and high scalability; disadvantages involve reduced control, security concerns, and variable performance.

Major providers: Amazon Web Services, Google Cloud, Microsoft Azure.

Private Cloud

Private clouds are dedicated to a single organization and can be deployed on‑premise or off‑premise. On‑premise private clouds reside in the organization’s own data center, offering tighter security and control but limited scalability. Off‑premise private clouds are managed by third‑party providers, offering lower cost and easier scaling.

Key providers: IBM and Amazon.

Hybrid Cloud

Hybrid cloud combines public and private clouds, allowing workloads to move between them while maintaining separate ownership. This model leverages the scalability and cost benefits of public clouds for non‑critical workloads and the security of private clouds for sensitive data.

Major providers: IBM and Microsoft.

Market Overview

The 2018 Q3 cloud industry report highlighted that spending is increasingly concentrated among a few dominant vendors—Amazon, Microsoft, and Alibaba—who together control over 55% of the market. Goldman Sachs predicts this combined share will reach 84% by 2019.

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

IDC forecasts that hybrid cloud will account for 67% of the overall cloud market, reflecting a shift toward multi‑cloud strategies.

Conclusion

Cloud computing in 2018 entered a transition phase where deep integration with vertical industries accelerated. Policy support and growing customer acceptance favor cloud adoption, yet small and medium enterprises still face significant challenges competing with the dominant players.

Ultimately, the market is moving toward an oligopoly dominated by Amazon AWS, Microsoft Azure, Alibaba Cloud, and Google Cloud, while smaller providers must focus on niche segments.