glossary.rmd

```{r, include = FALSE}
ottrpal::set_knitr_image_path()
```
Container
: A collection of software and dependencies that can run on nearly any machine with the same hardware architecture.

Docker
: A technology that allows you to containerize software, and to run said containers.

Docker Image: 
: The “recipe” for building the software environment. Can be downloaded from a registry using `docker pull` or can be generated using a Dockerfile.

Docker Container
: An instance of an executable software environment created from a Docker image.

Dockerfile
: A recipe for installing software and its dependencies so it can be packaged as a Docker image. Dockerfiles typically start by pulling an existing Docker image to act as the base.

Execution Engine
: A program that executes WDL on files. It may execute them your own laptop, a HPC cluster, or a cloud computing platform. The two most commonly used computing engines are miniwdl and Cromwell.

Registry
: A collection of repositories that you pull Docker images from, such as Docker Hub, Google Container Registry, etc.

Task
: The primary unit of a WDL workflow. Contains inputs, bash commands to execute, and the outputs.

Workflow
: The top level of a WDL workflow. Contains calls to tasks. Has its own inputs and outputs, which can be passed on to tasks.