Cloud Computing

1. What is Virtualization?

Virtualization is the technology that allows you to create multiple virtual versions of something such as server's, devices, or network on a physical machine.

virtualization lets one powerful physical server run many virtual machines (VMs) at the same time.

Why Virtualization matters:

Saves hardware costs
Uses resources more efficiently
Makes it easier to deploy and manage systems
Foundation of cloud computing

2. Scalability

Scalability is the ability of a system to handle growth by increasing resources.

Example: When demand increases more users, more data, more traffic, and If your website starts getting more visitors, you add more servers so it doesn’t slow down, a scalable system can expand to keep performance stable.

3. Agility

In IT and cloud computing, agility means the ability to quickly adapt to change.

Instead of waiting weeks to buy and set up new hardware, you can deploy new servers, apps, or services in minutes.

A startup launches a new feature today because they can instantly spin up cloud servers — not wait for physical equipment.

4. High Availability

High Availability means a system is designed to stay up and running with minimal downtime. even if one part fails, another one takes over automatically.

It keeps services available 99.9% - 99.999% of the time and its called "Uptime"

5. Fault Tolerant

Fault Tolerance goes a step further than high availability.

It means a system continues to operate without interruption at all, even when hardware or components fail.

Two systems run at the same time with identical data.
If one fails, the other continues instantly with zero disruption.

6. Global Reach

Global Reach refers to the ability of a system or cloud provider to deliver services to users all around the world.

Cloud providers have data centers in multiple countries and regions, allowing applications to run closer to users.

A user in South Africa connects to a nearby data center instead of one in the US, so the application loads faster.

7. What is the difference between Elasticity and Scalability

Elasticity
Elasticity = Flexibility

• Ability to automatically adjust capacity up and down based on demand
• Short-term demand changes
• Usually automatic
• Adding servers during a traffic spike, then removing them when traffic drops

Scalability
Scalability = Growth

• Ability to increase capacity to handle growth
• Long-term growth
• Often manual or planned
• Adding more servers because your app is growing