Azure基础（一）云的概念 - 云计算的原理

Learning objectives
In this module, you will:

• Explore common cloud computing services
• Explore the benefits of cloud computing
• Decide which cloud deployment model is best for you

Cloud computing is renting resources, like storage space or CPU cycles, on another company‘s computers.

You only pay for what you use. The company providing these services is referred to as a cloud provider.

Some example providers are Microsoft, Amazon, and Google.

The cloud provider is responsible for the physical hardware required to execute your work, and for keeping it up-to-date.

The computing services offered tend to vary by cloud provider. However, typically they include:

Compute power - such as Linux servers or web applications
Storage - such as files and databases
Networking - such as secure connections between the cloud provider and your company
Analytics - such as visualizing telemetry and performance data

Compute power
VMs aren‘t the only computing choice - there are two other popular options: containers and serverless computing.

A VM is an emulation of a computer - just like your desktop or laptop you‘re using now.
Each VM includes an operating system and hardware that appears to the user like a
physical computer running Windows or Linux.
You can then install whatever software you need to do the tasks you want to run in the cloud.

Containers provide a consistent, isolated execution environment for applications.
They‘re similar to VMs except they don‘t require a guest operating system.
Instead, the application and all its dependencies is packaged into a "container"
and then a standard runtime environment is used to execute the app.
This allows the container to start up in just a few seconds
because there‘s no OS to boot and initialize.
You only need the app to launch.

Serverless computing lets you run application code without creating, configuring, or maintaining a server.
The core idea is that your application is broken into separate functions that run when triggered by some action.
This is ideal for automated tasks - for example, you can build a serverless process
that automatically sends an email confirmation after a customer makes an online purchase.

Cloud computing makes running a business easier.
It’s cost-effective, scalable, elastic, current, reliable, and secure.
This means you’re able to spend more time on what matters and less time managing the underlying details.

Economies of scale is the ability to do things more efficiently or at a lower-cost per unit
when operating at a larger scale. This cost advantage is an important benefit in cloud computing.

These two approaches to investment are referred to as:

Capital Expenditure (CapEx): CapEx is the spending of money on physical infrastructure up front, and then
deducting that expense from your tax bill over time. CapEx is an upfront cost,
which has a value that reduces over time.

Operational Expenditure (OpEx): OpEx is spending money on services or products now and being billed for them now.
You can deduct this expense from your tax bill in the same year.
There‘s no upfront cost. You pay for a service or product as you use it.