mirror of https://github.com/docker/docs.git
42 lines
1.7 KiB
Markdown
42 lines
1.7 KiB
Markdown
---
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description: Getting started with Docker
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keywords: beginner, getting started, Docker
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redirect_from:
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- /mac/step_two/
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- /windows/step_two/
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- /linux/step_two/
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title: Learn about images and containers
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---
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Docker Engine provides the core Docker technology that enables images and
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containers. As the last step in your installation, you ran the
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`docker run hello-world` command. The command you ran had three parts.
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An *image* is a filesystem and parameters to use at runtime. It doesn't have
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state and never changes. A *container* is a running instance of an image.
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When you ran the command, Docker Engine:
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* checked to see if you had the `hello-world` software image
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* downloaded the image from the Docker Hub (more about the hub later)
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* loaded the image into the container and "ran" it
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Depending on how it was built, an image might run a simple, single command and
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then exit. This is what `hello-world` did.
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A Docker image, though, is capable of much more. An image can start software as
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complex as a database, wait for you (or someone else) to add data, store the
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data for later use, and then wait for the next person.
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Who built the `hello-world` software image though? In this case, Docker did but
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anyone can. Docker Engine lets people (or companies) create and share software
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through Docker images. Using Docker Engine, you don't have to worry about
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whether your computer can run the software in a Docker image — a Docker
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container *can always run it*.
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## Where to go next
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See, that was quick wasn't it? Now, you are ready to do some really fun stuff
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with Docker. Go on to the next part [to find and run the whalesay
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image](step_three.md). |