Cloud Computing Basics · Topic 1 of 1
Cloud Computing Concepts and Technologies
Learn IT development trends, the NIST cloud definition and five characteristics, IaaS, PaaS and SaaS, deployment models and the core cloud technologies.
- 5 min
- Five characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, measured service.
- IaaS delivers infrastructure, PaaS a platform, SaaS a finished application; user control falls from IaaS to SaaS.
- Deployment models: private, public, hybrid and community.
What it is
Cloud computing delivers compute, storage, network and software as services over a network. Users take resources from a shared pool on demand and pay for what they use, while the provider owns and runs the hardware.
It grew out of a long IT trend. Enterprises moved from separate physical servers for each application, to virtualized resource pools, to services consumed from a cloud.
How it works
IT development trends
Traditional IT gave each application its own servers, storage and network. Hardware was sized for the peak load, so average utilization was low. Adding capacity took weeks.
Digital transformation changed the demand. Mobile internet, IoT, big data and AI produce far more data and much more variable loads. Businesses need new services online in days, and cloud computing answers this with pooled resources provisioned in minutes.
Huawei describes the evolution of cloud computing in three stages.
| Stage | Focus | What changes |
|---|---|---|
| Cloud computing 1.0 | Virtualization of IT infrastructure | Physical servers become VMs on shared hosts, so utilization rises |
| Cloud computing 2.0 | Resource services and management | Self service, automated provisioning and unified management of resource pools |
| Cloud computing 3.0 | Enterprise applications | Distributed, microservice and container based cloud native applications |
The definition and five characteristics
The definition most courses use comes from NIST (SP 800-145). Cloud computing is a model for convenient, on-demand network access to a shared pool of configurable computing resources. Those resources can be rapidly provisioned and released with minimal management effort.
| Characteristic | Meaning |
|---|---|
| On-demand self-service | Users obtain resources themselves, without a request to the provider's staff |
| Broad network access | Resources are reached over the network from many kinds of devices |
| Resource pooling | Physical resources serve many tenants and are assigned dynamically |
| Rapid elasticity | Capacity scales out and in quickly, often automatically |
| Measured service | Use is metered, so it can be monitored, controlled and billed |
Service models
| Model | The provider delivers | The user manages | Example |
|---|---|---|---|
| IaaS | Compute, storage and network resources | OS, middleware, applications, data | A cloud server (VM) |
| PaaS | A platform: runtime, database, middleware | Applications and data | A managed database or application hosting platform |
| SaaS | A complete application | Only its own data and settings | Web email, online office software |
The higher the model, the more the provider manages and the less the user controls.
Deployment models
- Private cloud: built for one organization, in its own data center or hosted for it by a third party. It gives the most control over data and security.
- Public cloud: run by a provider and shared by many customers over the internet, such as Huawei Cloud.
- Hybrid cloud: a private cloud and a public cloud connected, so loads or data can move between them. A common case is bursting to the public cloud at peak.
- Community cloud: shared by several organizations with common needs, such as a group of government agencies.
Mainstream cloud computing technologies
A cloud is built from several layers of technology.
| Technology | Role in the cloud |
|---|---|
| Compute virtualization | Splits physical servers into VMs, for example KVM based hosts in Huawei FusionCompute |
| Storage virtualization and distributed storage | Pools disks across arrays or servers into datastores and volumes |
| Network virtualization | Virtual switches, VLANs, overlays and SDN give tenants their own networks |
| Cloud management platform | Manages pools, tenants, quotas and self service, for example OpenStack |
| Containers and cloud native | Lightweight application packaging and microservices on top of the cloud |
| Desktop cloud | Delivers desktops from the data center to thin clients, for example FusionAccess |
Virtualization creates the resource pools; cloud computing adds self service, elasticity, metering and management on top.
A worked example
A retailer runs its web shop on physical servers sized for the holiday peak, which sit mostly idle the rest of the year. It moves the shop to IaaS VMs. On normal days four VMs run, and before a sale a scaling policy adds more, then releases them when load drops.
The shop pays only for the VM hours used, which is measured service. It adds VMs from a console without a purchase order, which is on-demand self-service. Sharing the provider's hardware is resource pooling.
How the exam asks about this
- "Which of the following are characteristics of cloud computing?" → On-demand self-service, broad network access, resource pooling, rapid elasticity and measured service.
- "In which service model does the user manage the guest operating system?" → IaaS.
- "Which deployment model connects a private cloud with a public cloud?" → Hybrid cloud.
What to remember for the exam
- Five characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, measured service.
- IaaS delivers infrastructure, PaaS a platform, SaaS a finished application; user control falls from IaaS to SaaS.
- Deployment models: private, public, hybrid and community.
- Huawei's stages: 1.0 virtualization of infrastructure, 2.0 resource services and management, 3.0 cloud native enterprise applications.
- Virtualization is the foundation of cloud computing, but cloud computing adds self service, elasticity and metering.
"Virtualized" is not the same as "cloud". A virtualized data center without self service, elasticity and metering is not yet a cloud.
Common mistakes
Placing the OS in the wrong model. In IaaS the user installs, patches and secures the guest OS. In PaaS and SaaS the provider manages it.
Thinking a private cloud must be on premises. A private cloud is dedicated to one organization. A third party can host it and it is still private.
Confusing resource pooling with rapid elasticity. Pooling is about many tenants sharing the same hardware. Elasticity is about how quickly capacity grows and shrinks.
Check yourself
Which cloud characteristic makes pay-per-use billing possible?
Measured service. Usage is metered, so the provider can monitor, control and bill it.
A company rents a managed database and only loads its own tables and application. Which service model is this?
PaaS. The provider runs the platform, and the user manages only the application and its data.
What does Huawei's cloud computing 1.0 stage focus on?
Virtualization of IT infrastructure, which turns physical servers into VMs on shared hosts and raises utilization.
Topic 1 of 1 in Cloud Computing Basics
Test yourself on Cloud Computing Basics
The full Huawei H13-511 question bank has 600 questions, with timed practice exams and an explanation for every answer.
This study guide is independent and is not affiliated with, endorsed by, or sponsored by Huawei. Vendor names, certification names and exam codes are trademarks of their respective owners and are used for identification only.