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Docker packages an application together with everything it needs to run (code, libraries, settings) into a container, so it behaves the same on any machine. It solves the classic problem of software that works on one computer but breaks on another, because the environment travels with the app.
A container is like a standardized shipping box for software: the same box loads onto a developer's laptop, a test server, or a production cloud, and runs identically. That consistency makes deployment and scaling far more reliable.
For simple sites you may never touch Docker directly, since many hosts handle this for you. For larger or more complex systems, containers are a standard way to keep environments consistent and to run many services together predictably.
Updated July 2026
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A tech stack is the set of technologies a product is built with: the language, framework, database, and hosting. Choose based on what you're building, your team's skills, the ecosystem's maturity, and the ability to hire people who know it, not on what's newest or most talked about.
CI/CD (continuous integration and continuous delivery) is an automated pipeline that checks and ships code. When a developer pushes a change, CI automatically runs tests and checks to catch problems, and CD automatically deploys the change if it passes. It makes releasing software faster, safer, and routine.
Git is the standard tool for tracking changes to code. It records every edit as a snapshot, so a team can work on the same project at once, see who changed what, and roll back to any earlier version. Almost every software project uses it. Working without it is like writing without an undo button.
Git is the tool that tracks code changes on your computer. GitHub is an online service that hosts Git projects so teams can store, share, and collaborate on them in the cloud. Git is the technology, GitHub is a popular place to keep and work on Git projects. GitLab and Bitbucket are alternatives.
Version control is the practice of recording every change to a project over time, so you can see its history, work in parallel, and undo mistakes. Git is the dominant version-control system. It matters because it turns code from a fragile single copy into a safe, traceable, collaborative thing.
A package manager installs and manages the outside code libraries a project depends on. npm handles JavaScript packages, pip handles Python, and most languages have one. Instead of manually downloading and updating libraries, you list what you need and the package manager fetches the right versions.