Introduction to Docker

Introduction to Docker Learn containerisation from the ground up — the technology behind modern software delivery

Have you ever heard a developer say "but it works on my machine"?

Every technology team in the world knows that phrase — and the hours of frustration behind it. An application works perfectly in one environment, then breaks in another. Different operating systems, different library versions, different configurations — and suddenly nobody knows why the same code behaves differently in two places.

Docker solved that problem — and in doing so, changed how the entire software industry builds, ships, and runs applications. By packaging an application together with everything it needs to run into a single, portable unit called a container, Docker guarantees that software behaves identically everywhere: on a developer's laptop, on a test server, and in production across any cloud.

Today, containers are the standard unit of modern software delivery. Docker is the tool that made them mainstream — and understanding it is now a foundational skill for anyone working in development, operations, cloud, or DevOps.

This course is where you learn it properly.

What this course is about

Docker is one of those technologies that sounds more complicated than it is. Strip away the jargon, and the core ideas are remarkably intuitive — and once they click, a whole world of modern technology suddenly makes sense: containers, images, registries, Kubernetes, microservices, and the entire cloud-native ecosystem all build on the foundations this course teaches.

This programme gives you a clear, practical, hands-on introduction to Docker from first principles. You will learn what containers are and how they actually work, build and run your own containers from the very first session, create your own container images, and develop the practical fluency to use Docker confidently in real development and operations workflows.

By the end of this course, the technology that powers modern software delivery won't be a mystery — it will be a tool you know how to use.

No prior Docker or containerisation experience is required.

Why Docker skills matter right now

Containers have become the default way modern software is packaged and deployed. Cloud providers build their platforms around them. Development teams structure their workflows around them. Orchestration platforms like Kubernetes — one of the most in-demand technologies in the world — exist entirely to manage them.

And it all starts with Docker. Docker is the entry point to the entire cloud-native ecosystem — the first technology to learn, and the foundation everything else builds on. Whether your goal is DevOps engineering, cloud architecture, platform engineering, or modern software development, Docker fluency is the baseline expectation in virtually every job description.

The good news: it is also one of the most learnable technologies in that ecosystem — and one day of structured, hands-on training is enough to build a genuinely useful working capability.

What you will learn

• What containers are, how they work, and how they differ from virtual machines — explained clearly and without jargon
• Why containerisation has transformed how software is built, shipped, and deployed
• The core Docker concepts: images, containers, registries, and the Docker engine — and how they fit together
• How to run, manage, inspect, and troubleshoot containers using the Docker command line
• How to build your own container images using Dockerfiles — packaging real applications step by step
• How image layers work and how to write efficient, well-structured Dockerfiles
• How to manage data in containers using volumes — keeping data safe beyond the container lifecycle
• How container networking works — connecting containers to each other and to the outside world
• How to use Docker Hub and container registries to store, share, and pull images
• How to run multi-container applications using Docker Compose
• How Docker fits into the broader ecosystem — including Kubernetes, CI/CD pipelines, and cloud container services

How you will learn it

Docker is a hands-on technology, and this is a hands-on course. You will be running containers within the first hour — and by the end of the day you will have built your own images, managed real containers, configured networking and storage, and deployed a complete multi-container application.

Every concept is introduced with clear explanation before being applied in practice — so you always understand not just what to type, but what's actually happening when you do.

Every session is delivered by an active industry professional with real-world experience using Docker in production environments.

Flexible delivery — designed around your life

We offer multiple training formats so you can learn in the way that works best for you:

One-to-one (1:1) Private, personalised sessions scheduled around your availability.

Group training (cohort) Prefer to learn alongside others? Our weekend cohort sessions bring motivated learners together in a structured, collaborative environment — ideal if you enjoy working through practical exercises with a group and want to build connections with like-minded professionals along the way.

What's included

• Personalised Introduction to Docker training plan
• Hands-on labs building and running real containers throughout
• Access to an expert trainer before, during, and after every session
• Guidance on study materials, practice environments, and next steps
• A clear pathway toward Kubernetes, DevOps, and cloud-native learning paths

Who this is for

This course is designed for anyone who wants to understand and work with containers — regardless of background or prior experience. It is particularly well suited to:

Complete beginners to containerisation If you've heard the words "Docker" and "containers" everywhere but never quite understood what they mean, this course starts from absolute first principles and builds your knowledge step by step. No assumptions, no skipped explanations.

Developers who want to containerise their applications If you build software and want to package, run, and ship it the way modern teams do, Docker is the essential skill — and this course teaches it in the most direct, practical way possible.

IT professionals and system administrators moving toward DevOps If you manage infrastructure or support applications and want to transition into modern, container-based workflows, this course gives you the foundation that every DevOps role is built on.

Cloud engineers expanding their skill set If you already work with AWS, Azure, or Google Cloud and want to understand the container services those platforms offer — ECS, EKS, AKS, GKE, Cloud Run — Docker is the prerequisite knowledge that makes all of them make sense.

Anyone preparing to learn Kubernetes Kubernetes manages containers — which means understanding containers comes first. This course is the recommended starting point before our Introduction to Kubernetes programme, and the two together form a natural learning sequence.

Recommended prior experience: Basic familiarity with command-line tools is helpful, but not essential. No programming or infrastructure experience is required. If you're unsure whether you're ready, speak to one of our advisers and we'll give you an honest assessment.

Your outcome

You will complete this course with a genuine, practical understanding of Docker — not just what containers are, but the hands-on ability to build, run, manage, and troubleshoot them in real environments. You will understand how containerisation fits into modern software delivery, be ready to move confidently into Kubernetes and the broader cloud-native ecosystem, and have one of the most universally required skills in modern technology firmly under your belt.

Every cloud-native journey starts with containers. This course is where yours begins.

Not sure if this is the right starting point, or want to understand how it fits into your broader learning goals? Speak to one of our advisers — no commitment, no pressure, just an honest conversation about where you want to go and the best way to get there.

A note on certification

This course is designed to give you a solid, practical introduction to Docker and containerisation. While it provides the essential foundation, a one-day introduction is not sufficient preparation for the Docker Certified Associate exam on its own — certification requires deeper study, extensive hands-on practice, and dedicated exam preparation beyond what a single introductory course can provide. If certification is your goal, speak to one of our advisers and we will map out the full learning path to get you there.

Course curriculum

Introduction to Docker

Why containers? From "works on my machine" to modern software delivery

Before running your first container, you need to understand the problem containers were built to solve — and why they have transformed the entire software industry. This module sets that context, giving you the mental model that makes everything else in the course fall into place.

You will start by examining how applications have traditionally been deployed — directly onto servers and virtual machines — and the problems that approach creates: inconsistent environments, dependency conflicts, painful deployments, and the infamous gap between "it works on my machine" and "it's broken in production." From there you will learn what a container actually is — a lightweight, isolated, portable package containing an application and everything it needs to run — and how containers differ from virtual machines in architecture, performance, and use case.

The module then introduces Docker itself: what it is, where it came from, and the role each of its components plays — the Docker engine, the command-line client, images, containers, and registries. You will install Docker, verify your environment, and run your very first container before the module ends.

Working with containers

With the fundamentals in place, this module makes you fluent in the day-to-day work of running and managing containers — the commands and concepts you will use constantly in any container-based environment.

You will learn the full lifecycle of a container: pulling images from a registry, starting containers in the foreground and background, listing what's running, stopping, restarting, and removing containers cleanly. You will learn how to pass environment variables into containers, publish ports so containerised applications can be reached from outside, and set resource constraints so a single container can't consume an entire machine.

The module also builds your inspection and troubleshooting skills — viewing container logs, inspecting container configuration and state, executing commands inside a running container, and attaching to a container interactively to diagnose problems from the inside. These are the practical skills that turn conceptual understanding into genuine working capability.

Container images and Dockerfiles

Running other people's containers is useful — but the real power of Docker comes when you start packaging your own applications. This module teaches you how container images work and how to build your own.

You will start with a clear understanding of what an image actually is — a layered, read-only template from which containers are created — and how the layer system works: why layers make images efficient to build, store, and distribute, and how changes to an image affect its layers. Understanding layers is the key to writing good Dockerfiles, and this module makes sure you do.

From there you will learn the Dockerfile — the recipe that defines how an image is built. You will work through the essential instructions step by step: choosing a base image with FROM, copying application files with COPY, installing dependencies with RUN, configuring the runtime environment with ENV and WORKDIR, exposing ports with EXPOSE, and defining what the container runs with CMD and ENTRYPOINT. You will build a real application image from scratch, tag it properly, and understand the conventions behind image naming and versioning.

The module closes with the practices that distinguish good images from bloated ones — ordering instructions to make the most of layer caching, keeping images small, and an introduction to multi-stage builds for producing lean production images.

Storage and networking

Real applications need to store data and talk to other systems — and containers handle both differently from traditional servers. This module covers the storage and networking models that every Docker practitioner needs to understand.

On the storage side, you will learn why containers are ephemeral by design — anything written inside a container disappears when the container is removed — and how Docker solves that with volumes. You will learn the difference between volumes and bind mounts, when to use each, and how to attach persistent storage to containers so databases and stateful applications can survive container restarts and replacements.

On the networking side, you will learn how Docker networking works from the ground up: how containers get their own network namespace, how the default bridge network behaves, and how to create user-defined networks where containers can find each other by name. You will connect multiple containers together over a shared network, publish container ports to the host, and understand the patterns used to expose containerised applications to the outside world.

Registries and sharing images

An image on your laptop is only useful to you. Registries are how images are stored, shared, and distributed — within teams, across organisations, and around the world. This module covers how they work and how to use them.

You will start with Docker Hub — the world's largest public container registry — learning how to find and evaluate public images, understand official and verified images, and recognise the security considerations involved in pulling images from public sources. From there you will create your own repository, log in from the command line, and push your own images so they can be pulled and run anywhere.

The module also introduces private registries — the registries organisations run to store their own internal images — and the cloud-hosted registry services offered by the major providers, including Amazon ECR, Google Artifact Registry, and Azure Container Registry. You will understand image tagging strategies for versioning and releases, and how registries fit into the automated build and deployment pipelines used in professional environments.

Multi-container applications with Docker Compose

Real-world applications are rarely a single container — a typical application might involve a web frontend, an API, a database, and a cache, all running together. This final module teaches you how to define and run multi-container applications cleanly using Docker Compose.

You will learn what Docker Compose is and the problem it solves — replacing long sequences of manual docker commands with a single declarative YAML file that describes your entire application stack. You will write a compose file from scratch: defining multiple services, connecting them over networks, attaching volumes, setting environment variables, and controlling startup dependencies between services.

You will then bring a complete multi-container application to life with a single command — and learn the day-to-day Compose workflow of starting, stopping, rebuilding, and viewing logs across the whole stack. The module closes by connecting everything you've learned to what comes next: how the concepts behind Compose lead naturally into container orchestration, and where Kubernetes picks up when applications need to run at scale across many machines.

Where this course can take you

Docker is the gateway to the entire cloud-native world. Once you've completed this introduction, several valuable paths open up directly from here:

Introduction to Kubernetes The natural next step. Once you understand containers, Kubernetes — the industry-standard platform for orchestrating them at scale — is where the most in-demand skills in the ecosystem live. Our Kubernetes course builds directly on everything you learn here.

Introduction to Terraform Pair your container skills with infrastructure as code — learning to provision and manage the cloud environments your containers run in, using the industry-standard tooling.

AWS Certified DevOps Engineer — Professional Take your container knowledge into the full AWS DevOps ecosystem — CI/CD pipelines, Amazon ECS and EKS, and enterprise-scale automated delivery.

Google Cloud Professional DevOps Engineer Apply your Docker skills within the Google Cloud ecosystem — working with Google Kubernetes Engine, Cloud Run, and Google Cloud's delivery toolchain.

Docker Certified Associate (DCA) For those who want to formalise their Docker expertise with the official certification, this course provides the foundational knowledge that dedicated exam preparation builds on.