Suggest an editImprove this articleRefine the answer for “What is Docker?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**Docker** is a platform that lets you run applications in isolated containers. **Key point:** Docker is a tool for packaging and running applications in containers, which makes development, testing, and deployment faster, simpler, and safer.Shown above the full answer for quick recall.Answer (EN)Image**Docker** is a platform that lets you **run applications in isolated containers**. A container is like a "mini-computer" inside your system: it has everything the program needs to run - code, dependencies, libraries, and settings. ### How it works - Instead of installing everything manually (PostgreSQL, Python, Nginx, and so on) on your computer, you create a **container** - a packaged environment where everything is already configured. - Containers run on top of a single operating system, but are isolated from each other. - They can be easily **started, stopped, copied, and moved** to other machines without changing the code. ### Example You want to run PostgreSQL: instead of installing it - ```bash docker run -d -p 5432:5432 postgres ``` and in seconds you have a working database running in a container. ### Why Docker is needed 1. **Isolation** - each project runs in its own environment and does not conflict with others. 2. **Portability** - the container can run on any server that has Docker. 3. **Fast deployment** - easy to deploy a copy of an application or database. 4. **Environment consistency** - "it works on my machine" = "it works everywhere". **Key point:** Docker is a tool for packaging and running applications in containers, which makes development, testing, and deployment faster, simpler, and safer.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.