What is Docker and How to Install It: A Beginner’s Guide

What is Docker?

Docker is a platform designed to simplify the development, deployment, and operation of applications by using containers. It’s an open-source tool, written in Go, that enables OS-level virtualization. Containers allow applications to run in isolated environments with all their dependencies, making them portable and lightweight.

Key Concepts:

1. Docker Engine: This is the core part of Docker. It acts as the heart of the Docker platform, responsible for running and managing containers.

2. Docker Daemon: A background service that manages containers. It listens for API requests and controls Docker objects like images and containers.

3. Docker Client: The command-line tool that allows you to interact with the Docker Daemon.

4. Docker Hub: A cloud-based repository where you can find pre-built images, share your own, or pull images for your projects.

Advantages of Docker Over Virtual Machines (VMs):

• Lightweight: Docker containers share the host OS kernel, making them much more lightweight than VMs.

• Faster Startup: Containers start almost instantly, compared to VMs which take time to boot up.

• Efficient Resource Usage: Containers use less memory and CPU than VMs.

Installing Docker:

You can install Docker by following the official installation guide for your operating system here.
After installation, verify Docker is running by using:

bashCopy codedocker --version

Docker Components:

• Docker Image: A lightweight, standalone, and executable package that contains everything needed to run a piece of software, including code, runtime, libraries, and settings.

• Docker Container: A running instance of a Docker image. Think of it as an isolated environment that runs your application.

Docker Architecture:

Docker follows a client-server architecture. The client sends commands to the Docker Daemon, which does the heavy lifting of building, running, and managing containers.