What Is Cloud Computing?

What Is Cloud Computing?

Renting Computing Over the Internet

Cloud computing means renting computing resources - servers, storage, databases, and networking - over the internet instead of buying and maintaining physical hardware. A provider such as AWS, Azure, or Google Cloud owns vast data centers and lets you consume a slice of them on demand, paying only for what you use.

Before the cloud, a company bought a server, installed it on site, and waited weeks for shipping and setup. Now a virtual server can be ready in minutes, scaled up during traffic spikes, and released when it is no longer needed.

The Three Big Service Models

Cloud services come in three main flavors, differing in how much you manage:

• Infrastructure as a Service (IaaS): you rent raw computing resources - virtual machines, storage, and networks - and manage the operating system and everything above it.
• Platform as a Service (PaaS): the provider manages the runtime, databases, and middleware, so you focus only on your application code.
• Software as a Service (SaaS): the provider delivers a complete finished application you use through a browser, such as email or office tools.

Think of it like dining: IaaS is buying raw ingredients, PaaS is a ready-to-cook meal kit, and SaaS is a restaurant meal.

Key Cloud Advantages

The cloud's advantages drive its adoption:

• Elastic scaling: resources grow or shrink automatically with demand.
• Pay-as-you-go billing: you pay for consumed resources, not idle ones.
• Global reach: deploy applications in data centers close to users worldwide.
• Managed services: patching and backups become the provider's problem.

The Shared Responsibility Model

Security is divided. The provider secures the physical data center, network, and hypervisor. You secure what you build: operating systems you run, application code, access credentials, and data. Misunderstanding this boundary is a common source of cloud security incidents.

Key Points

• Cloud computing rents computing resources on demand over the internet.
• IaaS gives raw infrastructure; PaaS gives a managed platform; SaaS gives finished software.
• Scaling, pay-as-you-go pricing, and global reach are core benefits.
• Security is shared: the provider owns infrastructure, and you own what you deploy.
• Cloud resources deploy in minutes instead of weeks of procurement.