4.2 Cloud Models

Q: What is cloud computing?

A: Delivering computing resources (servers, storage, apps) over the internet with scalable, on-demand access.

Q: What is a key advantage of cloud computing over traditional infrastructure?

A: Rapid deployment—resources can be created or removed in minutes instead of buying and setting up hardware.

Q: What does “elasticity” in cloud computing mean?

A: The ability to quickly scale resources up or down based on demand.

Q: What is meant by “international scope” in cloud computing?

A: You can deploy services in data centers around the world close to users.

Q: What does “pay-as-you-go” mean in the cloud?

A: You only pay for the resources you use.

Q: What is a public cloud?

A: Cloud services available to anyone over the internet (e.g., AWS, Microsoft Azure).

Q: What is a private cloud?

A: A cloud environment dedicated to a single organization.

Q: What is a hybrid cloud?

A: A combination of public and private cloud environments.

Q: What is a community cloud?

A: A shared cloud environment used by multiple organizations with similar needs.

Q: What is Infrastructure as a Service (IaaS)?

A: Renting virtualized hardware (servers, storage) where you manage OS, updates, and security.

Q: What is another name for IaaS?

A: Hardware as a Service (HaaS).

Q: What are your responsibilities in IaaS?

A: Managing OS, applications, security, and updates.

Q: What is Software as a Service (SaaS)?

A: Fully managed applications delivered over the internet with no local installation.

Q: Give examples of SaaS.

A: Microsoft 365, Proton Mail.

Q: What is Platform as a Service (PaaS)?

A: A platform for developing applications without managing hardware or OS.

Q: What is your responsibility in PaaS?

A: Application development and data management.

Q: What is a key difference between IaaS, PaaS, and SaaS?

• IaaS: You manage most things

• PaaS: You manage apps

• SaaS: Provider manages everything

Q: What is a responsibility matrix in cloud computing?

A: A model that defines what the cloud provider manages vs. what the customer manages.

Q: What is multitenancy?

A: Multiple customers share the same cloud infrastructure securely.

Q: What is high availability in the cloud?

A: Systems remain accessible due to redundancy across multiple data centers.

Q: What is file synchronization in the cloud?

A: Data is duplicated across multiple locations for consistency and availability.

Q: What is metered cloud usage?

A: Billing based on actual usage (storage, uploads, downloads).

Q: What is non-metered cloud usage?

A: Paying a fixed amount for a set level of resources.

Q: What is ingress traffic?

A: Data uploaded to the cloud.

Q: What is egress traffic?

A: Data downloaded from the cloud.

Q: What is a key difference between private and public cloud?

• Private: Owned and used by one organization

• Public: Shared and managed by a provider

Q: Which cloud model gives you the MOST control?

A: IaaS

Q: Which cloud model gives you the LEAST control?

A: SaaS

Q: Which cloud model is best for developers?

A: PaaS

Q: Which cloud feature ensures systems stay online even if hardware fails?

A: Redundancy (high availability)