Cloud Concepts

1.Virtualization
Virtualization is the process of creating a virtual version of physical resources such as servers, storage, networks, or operating systems.
It allows one physical computer to run multiple virtual machines (VMs), each acting like a separate computer.

Example:
A single physical server can host several virtual servers using software like VMware or Microsoft Hyper-V.

2.Scalability
Scalability is the ability of a system to handle increased workload by adding resources.

There are two main types:

Vertical Scaling (Scale Up): Increase CPU, RAM, or storage of one server.
Horizontal Scaling (Scale Out): Add more servers to share the workload.

Example:
Adding more web servers when website traffic increases.

3.Agility
Agility in cloud computing means the ability to quickly create, deploy, and manage resources or applications.

Cloud services allow businesses to:

• Deploy servers quickly
• Respond faster to customer needs
• Test and launch applications rapidly

Example:
Creating a new virtual machine in minutes instead of buying physical hardware that may take weeks.

4.High Availability
High Availability means a system remains operational for a very high percentage of time with minimal downtime.
The benefit/uses of High Availability are:

*Backup systems
*Redundant servers
*Automatic failover

Example:
If one server fails, another server immediately takes over to keep the application running.

5.Fault Tolerant
Fault tolerance is the ability of a system to continue operating even when one or more components fail.

Unlike high availability, fault tolerance aims for zero interruption.

Example:
Two identical systems run simultaneously. If one fails, the other continues instantly without users noticing.

6.Global Reach
Global reach refers to the ability of cloud services to deliver applications and services to users worldwide through multiple data centers and regions.

Benefits:

*Faster access for users
*Better performance
*Reduced latency

Example: Microsoft Azure and Amazon Web Services have data centers across many countries.

7.Difference Between Elasticity and Scalability

Elasticity	Scalability
Automatically adjusts resources based on demand	Increases resources to handle growth
Usually temporary	Usually long-term
Resources can increase and decrease automatically	Resources are added when needed
Common in cloud environments	Can exist in cloud or on-premises

Example

*Elasticity: A streaming app automatically adds servers during a live football match and removes them after traffic reduces.

*Scalability: A company permanently upgrades from 2 servers to 10 servers because the business has grown.