Thread by @FrancescoCiull4

🐳A thread of minimalistic definitions of some Docker elements:

- Docker host
- Docker engine
- Docker client
- Dockerfile
- Docker image
- Docker container
- Docker Compose
- Docker Registry
- Docker Swarm

Definitions Below 👇👇👇

//And by the way, I already know that it's...

Docker (Active) Host

A computer with Docker installed and the daemon running.
It can process Docker and non-Docker workloads.

Docker Engine

A Client-Server application. It has 3 components:

"daemon process": A server which is a type of long-running program.

"Rest API": to specify interfaces that programs can use to talk and interact with the daemon.

Docker Client

It sends commands to dockerd, using the Docker API.
It can communicate with multiple daemons.

Dockerfile

It's a text document that contains all the commands a user could call on the command line to assemble an image.

Docker Image

It's a file, composed of multiple layers, often based on another image, that contains everything you need in to run your application

Docker Container

It's a process, with some additional features, in order to keep it encapsulated and isolated, from the host machine and from other containers

Docker compose

It's a tool for defining and running multi-container Docker applications, called services.

You use a YAML file to configure the services, that can be created/started/stopped with a single command.

It works well in development, testing, and production.

Docker registry

It's a stateless server-side application to store Docker images. The images can be pulled or pushed.

It can be public/private.

Docker Hub is a public Docker registry.

Docker Swarm

It's a container orchestration tool.

It allows you to manage multiple containers deployed across multiple host machines (nodes).