AZ-900:Describe cloud concepts ③


AZ-900の試験を英語で受けるに至り、翻訳なしで勉強をしてまとめていく勉強ノートです。

自身の復習用としても記事を書くつもりではありますが、同じように英語で受講予定＆翻訳なしでそのまま英語で勉強した方がやりやすい方の参考に少しでもなることが出来ればと思います。

日本語で勉強をしたい方は、こちらのサイトを是非参考にしてみてください：

https://qiita.com/fsd-jume/items/17f551a1f93c0dace855

# 学習内容
**Intro to cloud computing: Describe the consumption-based model*
- [学習内容](#学習内容)
- [Describe the consumption-based model](#describe-the-consumption-based-model)
		- [CapEx](#capex)
		- [OpEx](#opex)
- [Compare cloud pricing models](#compare-cloud-pricing-models)
- [Check list:](#check-list)

<a id="#describe-the-consumption-based-model"></a>
# Describe the consumption-based model
Two types of expenses to consider when comparing IT infrastructure models:
* Capital expenditure (CapEx)
* Operational expenditure (OpEx)

### CapEx
One-time, up-front expenditure to purchase or secure resources
Examples:
* building a datacenter
* buying a company vehicle

### OpEx
Ongoing expenditure over time on services or products
Examples:
* signing up for cloud services
* renting a convention center
* **cloud computing**
  * operates on a consumption-based model
    * no need to pay for physical infrastructure
    * instead need to pay for the IT resources the consumer uses: no need to pay for a month that the IT resources are not used.

Benefits:
* No upfront costs.
* No need to purchase and manage costly infrastructure that users might not use to its fullest potential.
* The ability to pay for more resources when they're needed.
* The ability to stop paying for resources that are no longer needed.

Cons of CapEx(traditional data center) that consumers doesn't have to worry anymore in a cloud-based model:
* esitimation of future resource needs lead consumers to waste money / suffer from overestimating / underestimating.
* time consuming when fixation is needed: ordering, receiving, installing hardware... adding power, cooling, and networking for the extra hard ware.

<a id="#compare-cloud-pricing-models"></a>
# Compare cloud pricing models
Cloud computing:
* Delivery of computing services over the internet
* uses a pay-as-you-go pricing model, thus consumers pay only for cloud services they use.
  * helps plan and manage operating costs
  * helps run infrastructure more efficiently
  * helps to scale as bussiness needs change.
  * no need of maintaining CPUs and storage as consumers only have to rent when needed.
  * cloud provider takes care of maintaining the underlying infrastructure

# Check list:
by now, can you...
* Define cloud computing.
* Describe the shared responsibility model.
* Define cloud models, including public, private, and hybrid.
* Identify appropriate use cases for each cloud model.
* Describe the consumption-based model.
* Compare cloud pricing models.

If yes, way to go!
If no, try reviewing.

---

AZ-900:Describe cloud concepts① はこちら：

https://qiita.com/fsd-lukapyon/items/0100596156d3abc7808e

AZ-900:Describe cloud concepts② はこちら：

https://qiita.com/fsd-lukapyon/items/99edd38b566f6ed0d096

AZ-900:Describe cloud concepts④ はこちら：

https://qiita.com/fsd-lukapyon/items/90ed9d652da29f19f06e

AZ-900:Describe cloud concepts⑤ はこちら：

https://qiita.com/fsd-lukapyon/items/3d489123078f765ccb87

AZ-900:Describe cloud concepts⑥ はこちら：

https://qiita.com/fsd-lukapyon/items/6b5e612044dd37b42386

AZ-900:Describe cloud concepts⑦ はこちら：

https://qiita.com/fsd-lukapyon/items/83390ae397ff8e7b8989

AZ-900:Describe cloud concepts⑧ はこちら：

https://qiita.com/fsd-lukapyon/items/abfc398d55bf28160b90

AZ-900:Describe cloud concepts⑨ はこちら：

https://qiita.com/fsd-lukapyon/items/4881ce9db481dd4173eb