Containers vs Virtual Machines: What's the Difference?

What is a Container? A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, and settings. Ok, let me make it easy! A container is a bundle of: Application Application libraries required to run your application The minimum system dependencies Containers vs Virtual Machines Containers and virtual machines are both technologies used to isolate applications and their dependencies, but they have some key differences: 1. Resource Utilization Containers share the host operating system kernel, making them lighter and faster than VMs. VMs have a full-fledged OS and hypervisor, making them more resource-intensive. 2. Portability Containers are designed to be portable and can run on any system with a compatible host OS. VMs are less portable as they need a compatible hypervisor. 3. Security VMs provide a higher level of isolation and security as each has its own OS. Containers share the host OS kernel, which provides less isolation. 4. Management Containers are easier to manage as they are designed to be lightweight and fast-moving. Why Are Containers Lightweight? Containers are lightweight because they use containerization technology, allowing them to share the host OS kernel while still providing isolation for the app and its dependencies. This means: Smaller size compared to full VMs Minimal components needed to run the app Faster startup and deployment times Let’s Understand This with an Example: Below is the screenshot of the official Ubuntu base image used for containers. It's just ~22 MB!

May 3, 2025 - 19:25

Containers vs Virtual Machines: What's the Difference?

What is a Container?

A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another.

A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, and settings.

Ok, let me make it easy!

A container is a bundle of:

Application
Application libraries required to run your application
The minimum system dependencies

Containers vs Virtual Machines

Containers and virtual machines are both technologies used to isolate applications and their dependencies, but they have some key differences:

1. Resource Utilization

Containers share the host operating system kernel, making them lighter and faster than VMs.
VMs have a full-fledged OS and hypervisor, making them more resource-intensive.

2. Portability

Containers are designed to be portable and can run on any system with a compatible host OS.
VMs are less portable as they need a compatible hypervisor.

3. Security

VMs provide a higher level of isolation and security as each has its own OS.
Containers share the host OS kernel, which provides less isolation.

4. Management

Containers are easier to manage as they are designed to be lightweight and fast-moving.

Why Are Containers Lightweight?

Containers are lightweight because they use containerization technology, allowing them to share the host OS kernel while still providing isolation for the app and its dependencies.

This means:

Smaller size compared to full VMs
Minimal components needed to run the app
Faster startup and deployment times

Let’s Understand This with an Example:

Below is the screenshot of the official Ubuntu base image used for containers.

It's just ~22 MB!