Docker explained: how containers workDocker explained: what containers are, how Docker Engine uses Linux namespaces and cgroups, how images, Dockerfiles, and Docker Compose fit together, and how Docker compares with virtual machines.Containers vs Virtual Machines: which should you choose?Containers and virtual machines both isolate workloads, but they do it in fundamentally different ways. Compare architecture, performance, isolation, security, and use cases to pick the right one for your application.What is YAML? The complete guide to YAML syntax and use casesYAML (YAML Ain't Markup Language) is a human-readable data serialization format used for configuration files, CI/CD pipelines, and cross-language data exchange. This guide explains YAML syntax, key features, common tools, and security pitfalls.How to use Docker Compose: multi-container apps explainedLearn Docker Compose to run multi-container apps from one YAML file: services, networks, volumes, health checks, Compose Watch, env vars, docker compose up and common commands — with a real Node.js example.How to containerize a Node.js app with DockerContainerize a Node.js app with Docker: write a Dockerfile, use base images and multi-stage builds, expose ports, manage dependencies and environment variables, and run your container locally — open-license sources.Docker vs Kubernetes: which one do you need?Docker and Kubernetes solve different problems: Docker packages and runs one application in a container, while Kubernetes orchestrates many containers across a cluster of machines. Compare what each does, when you need orchestration, and how to choose.How to monitor a Node.js application with Prometheus and GrafanaBuild a complete Node.js + Prometheus + Grafana monitoring stack: instrument Express with prom-client, scrape metrics, run Prometheus in Docker, build Grafana dashboards with PromQL, and configure alerts. Includes a working docker-compose example. 