Docker is a platform for developing, shipping, and running applications in containers. Containers allow you to package an application and its dependencies into a standardized unit for software development. Here’s a basic guide on how to use Docker:

Installation:

• Before you start, make sure Docker is installed on your machine. You can download and install Docker from the official website: Docker Desktop.

Verify Installation:

• Open a terminal or command prompt and run the following commands to verify that Docker is installed correctly:
  

docker --version docker run hello-world

Docker Images:

• Docker images are the building blocks of containers. Images are lightweight, standalone, and executable packages that include everything needed to run an application, including the code, runtime, libraries, and dependencies.
• Pull an existing image from Docker Hub:
  

docker pull image_name:tag

Docker Containers:

• Containers are instances of Docker images. You can run multiple containers from the same image.
• Run a container:
  

docker run image_name:tag

• Run a container in detached mode (in the background):
  

docker run -d image_name:tag

• List running containers:
  

docker ps

• List all containers (including stopped ones):
  

docker ps -a

Dockerfile:

• Dockerfile is a script that contains instructions to build a Docker image. Create a file named Dockerfile in your project directory.
• Example
  

FROM ubuntu:latest
RUN apt-get update && apt-get install -y python3
CMD ["python3", "-c", "print('Hello, Docker!')"]

• Build an image from a Dockerfile:
  

docker build -t image_name:tag .

Volumes:

• Volumes allow you to persist data outside of the container. This is useful for storing database files, logs, or other data that should survive container restarts.
• Mount a volume when running a container:
  

docker run -v /host/path:/container/path image_name:tag

Networking:

• Docker containers can communicate with each other and the outside world through networking. You can expose ports and link containers.
• Expose a port when running a container:
  

docker run -p host_port:container_port image_name:tag

Compose:

• Docker Compose is a tool for defining and running multi-container Docker applications. It allows you to define services, networks, and volumes in a docker-compose.yml file.
• Example docker-compose.yml file:

version: '3'
services:
  web:
    image: nginx:alpine
    ports:
      - "8080:80"

• Run the services defined in a docker-compose.yml file:
  

docker-compose up

This is a basic overview of Docker usage. Docker provides a powerful set of commands and features for container management, orchestration, and more. Refer to the official Docker documentation for more in-depth information: Docker Documentation.