[**Dockerfiles**](https://docs.docker.com/engine/reference/builder/) are text documents that contain all commands a user could call in a terminal to assemble an application image.
[**Docker Compose**](https://docs.docker.com/compose/) uses [human-friendly YAML files](https://docs.photoprism.app/developer-guide/technologies/yaml/) to configure all application services so you can easily start them with a single command.
See our [Getting Started FAQ](https://docs.photoprism.app/getting-started/faq/#how-can-i-install-photoprism-without-docker) for alternative installation methods, for example using the [*tar.gz* packages](https://github.com/photoprism/photoprism/blob/develop/setup/pkg/linux/README.md) we provide for download at [dl.photoprism.app/pkg/linux/](https://dl.photoprism.app/pkg/linux/README.html).
**(1) Docker uses standard features of the Linux kernel.** Containers are nothing new; [Solaris Zones](https://en.wikipedia.org/wiki/Solaris_Containers) were released about 20 years ago and the chroot system call was introduced during [development of Version 7 Unix in 1979](https://en.wikipedia.org/wiki/Chroot). It is used ever since for hosting applications exposed to the public Internet. Modern Linux containers are an incremental improvement of this, based on standard functionality that is part of the kernel.
**(2) Docker saves time through simplified deployment and testing.** A main advantage of Docker is that application images can be [easily made available](https://hub.docker.com/r/photoprism/photoprism) to users via Internet. It provides a common standard across most operating systems and devices, which saves our team a lot of time that we can then spend [more effectively](https://docs.photoprism.app/developer-guide/code-quality/#effectiveness-efficiency), for example, providing support and developing one of the many features that users are waiting for.
**(3) Dockerfiles are part of the source code repository.** [Human-readable](https://docs.docker.com/engine/reference/builder/) and [versioned Dockerfiles](https://github.com/photoprism/photoprism/tree/develop/docker) that are part of our public source code help avoid "works for me" moments and other unwelcome surprises by enabling us to have the exact [same environment](http://localhost:8000/developer-guide/setup/) everywhere in [development](https://github.com/photoprism/photoprism/tree/develop/docker/develop), [staging, and production](https://github.com/photoprism/photoprism/tree/develop/docker/photoprism).
**(4) Running applications in containers is more secure.** Last but not least, virtually all file format parsers have vulnerabilities that just haven't been discovered yet. This is a known risk that can affect you even if your computer is not directly connected to the Internet. Running apps in a container with limited host access is an easy way to improve security without compromising performance and usability.
A virtual machine with a dedicated operating system environment provides even more security, but usually has side effects such as lower performance and more difficult handling. Using a VM, however, doesn't prevent you from running containerized apps to get the best of both worlds. This is essentially what happens when you install Docker on [virtual cloud servers](https://docs.photoprism.app/getting-started/cloud/digitalocean/) and operating systems other than Linux.
