MODULE 2: Virtual Machines & Hypervisor Fundamentals

This module explains how virtualization actually works.
You will learn what a Virtual Machine really is, how hypervisors control hardware, and how multiple systems safely run on one physical server.

This is the core technical foundation of virtualization and cloud computing.

What You Will Learn in This Module

By the end of Module 2, you will be able to:

• Explain what a Virtual Machine (VM) is
• Understand how CPU, RAM, storage, and network are virtualized
• Explain what a hypervisor does
• Differentiate between Type 1 and Type 2 hypervisors
• Understand VM isolation and security basics
• Understand the VM lifecycle from creation to deletion

Lesson 1: What Is a Virtual Machine (VM)?

Definition (Simple & Clear)

A Virtual Machine (VM) is a software-based computer that runs inside a physical computer.

A VM has:

• Virtual CPU
• Virtual RAM
• Virtual storage (virtual disk)
• Virtual network card
• Its own operating system

To the operating system inside it, a VM looks like a real physical computer.

Real-World Example

On one physical server, you can run:

• Windows Server VM
• Linux VM
• Database VM
• Application VM

All running at the same time, independently.

Lesson 2: Physical Server vs Virtual Machine

Lesson 3: How Hardware Is Virtualized

CPU Virtualization

• Physical CPU cores are shared
• Each VM gets virtual CPUs (vCPU)
• Hypervisor schedules CPU time fairly

Memory (RAM) Virtualization

• RAM is allocated to VMs
• Memory is isolated per VM
• Advanced features allow memory optimization

Storage Virtualization

• Virtual disks stored as files
• Can be expanded easily
• Supports snapshots and cloning

Network Virtualization

• Virtual Network Interface Card (vNIC)
• Connects VM to virtual switches
• Enables isolated or shared networks

Lesson 4: What Is a Hypervisor?

Definition

A hypervisor is the software layer that:

• Sits between hardware and VMs
• Allocates resources
• Controls VM access to hardware
• Ensures isolation and security

Without a hypervisor, virtualization is impossible.

Lesson 5: Types of Hypervisors

• Type 1 Hypervisor (Bare-Metal)

• Installed directly on hardware
• Used in data centers
• High performance and security

Examples (conceptual):

• VMware ESXi
• Microsoft Hyper-V
• KVM

• Type 2 Hypervisor (Hosted)

• Runs on top of an operating system
• Used for testing and learning
• Less performance than Type 1

Examples:

• VirtualBox
• VMware Workstation

Comparison

Lesson 6: VM Isolation & Security Basics

Each VM is:

• Isolated from others
• Has its own OS and memory space
• Cannot see other VMs unless allowed

If one VM crashes:

• Others continue running

This isolation is critical for security and stability.

Lesson 7: Virtual Machine Lifecycle

A VM goes through several stages:

1. Create – Allocate CPU, RAM, storage
2. Install OS – Windows or Linux
3. Run – Normal operation
4. Pause / Suspend – Temporary stop
5. Snapshot – Save current state
6. Clone – Create copy
7. Delete – Remove VM

This flexibility is a major advantage of virtualization.

Lesson 8: Snapshots & Templates (Conceptual)

Snapshots

• Capture VM state at a point in time
• Used before updates or changes
• Allow quick rollback

Templates

• Pre-configured VM images
• Used to create multiple identical VMs
• Save time and ensure consistency

Lesson 9: Why VMs Are Critical for Cloud Computing

Cloud platforms use VMs to:

• Provide compute resources on demand
• Scale quickly
• Isolate customers
• Optimize hardware usage

Every cloud server you create is:
A virtual machine managed by a hypervisor

MODULE 2 SUMMARIES

By completing Module 2, you now understand:

• What a Virtual Machine is
• How CPU, RAM, storage, and network are virtualized
• What a hypervisor does
• Differences between Type 1 and Type 2 hypervisors
• VM isolation and security basics
• VM lifecycle management

This module answers the key question:

“How can multiple operating systems safely run on one physical server?”