01 - Introduction

Docker

Docker is an open-source platform that enables developers to build, package, and run applications inside lightweight, portable containers. It ensures that software runs consistently across different environments — from a developer’s laptop to production servers.

By using Docker, you eliminate the classic “it works on my machine” problem. Applications are bundled together with all their dependencies, making them easy to ship, deploy, and replicate anywhere. This leads to faster development cycles, simpler deployments, and greater reliability.

Docker is the foundation of modern containerized workflows and works hand-in-hand with tools like Kubernetes. In this section, we will explore its key concepts and components, including:

• Images – templates used to create containers
• Containers – isolated environments where applications run
• Dockerfiles – instructions for building custom images
• Volumes – persistent data storage for containers
• Networks – communication between containers
• Docker Compose – defining and running multi-container applications
• Registries – storing and distributing container images

Understanding these fundamentals will give you a solid base for working with containers and preparing applications for scalable, cloud-native environments.