Hi,

Defence-in-depth is a security strategy that has been popular for a number of years (it pre-dates cloud computing). ... Defense in depth is an information assurance (IA) concept in which multiple layers of security controls (defense) are placed throughout an information technology (IT) system.

It includes domains such as cost, security and privacy, scalability, mutual performance and interoperability, implementation platform and independence ofCloud Computing, ability to search and exploration, reducing errors and improving the quality, structure, flexibility and sharing ability.

Best Wishes..

There are multiple Cloud Service Providers (CSPs) featuring their products and services under different brand names but when it comes to functionality, they are similar.

Cloud services cover broad range of applications, such as:

* Compute (for Information Processing Power using Virtual CPU and Virtual Memory)

* Storage (for Online Storage)

* Networking & Content Delivery (CDN) (for Pushing contents closer to users)

* Database (Structured or Relational, Key-Value , Column Family, Document, Graph, and Network)

* Analytics, Big Data, and Intelligence

* Internet of Things (IoT)

* Management and Monitoring

* Mobile Services

* Security Identity

* Access, Developer Tools

* Enterprise Integration and Marketplace.

Cloud Computing business is growing. Taking as an example of Infrastructure as a Service (IaaS), this market grew 31.3% in 2018 to total $32.4 billion, up from $24.7 billion in 2017, according to Gartner, Inc. [1]

Amazon Web Services (AWS), Microsoft Azure, Alibaba, Google Cloud Platform (GCP) and IBM are among the top ten players.

I will apple-to-apple compare the offerings of following big-three of CSPs [1], which are:

1- Amazon Web Services (AWS)

2- Microsoft Azure (Azure)

3- Google Cloud Platform (GCP).

For IaaS, Offerings are called:

*In AWS: Elastic Compute Cloud (EC2)

*In Azure: Virtual Machines

*In GCP: Google Compute Engine (GCE).

For Containers as a Services (CaaS), Offerings are called:

*In AWS: EC2 Container Services (ECS) Or EC2 Kubernetes Services (EKS).

*In Azure: Amazon Container Services (ACS) Or Amazon Kubernetes Services (AKS)

*In GCP: Google Kubernetes Engine (GKE).

Kubernetes is a de-facto production grade orchestrator for containers.

For Platform as a Service (PaaS), offerings are called:

*In AWS: Lambda

*In Azure: Azure Service Fabric (ASF)

*In GCP: Google Application Engine (GAE).

Top layer acting as Back-end Process Layer is called:

*In AWS: Lambda

*In Azure: Azure Functions or Event Grid

*In GCP: Cloud Functions.

TLDR;

Cloud Computing is an umbrella encompassing a panorama of offerings, products and services.This is why, multiple topics exist on it.

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[1] Gartner, Available, Online: https://www.gartner.com/, 2019

The Cloud computing definition I usually go by and find most useful is the National Institute of Standards and Technology here:

https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-145.pdf

It's good to differentiate cloud computing against what kind of computing capacity typically was provided before that. As a contrast, cloud computing is:

• Abstracted and offered as a service.
• Built on a massively scalable infrastructure.
• Easily purchased and billed by consumption.
• Shared and multi-tenant.
• Based on dynamic, elastic, flexibly
• Configurable resources.
• Accessible over the Internet by any device.

I would say that there are three really broad categories of service:

Infrastructure as a Service (IaaS)

Software as a Service (SaaS)

Platform as a Service (PaaS)

While there is a proliferation of * as a Service, such as Containers as a Service or Database as a Service, I would put Containers under that IaaS category and Database as a Service as SaaS or PaaS.

SaaS is a huge category not mentioned above. Vendors like Salesforce and Workday enable enterprises to have customer relationship management and human resources management functions performed in the cloud without having worry about handling their own hardware and software.

Note: above bullet points from our 10 year old white paper on Cloud Strategy:Article Developing an Enterprise Cloud Computing Strategy