GitLab CI/CD is configured by a file called `.gitlab-ci.yml` placed
at the repository's root. This file creates a [pipeline](pipelines/index.md), which runs for changes to the code in the repository. Pipelines consist of one or more stages that run in order and can each contain one or more jobs that run in parallel. These jobs (or scripts) get executed by the [GitLab Runner](https://docs.gitlab.com/runner/) agent.
To get started with GitLab CI/CD, we recommend you read through
the following documents:
-[Get started with GitLab CI/CD](quick_start/index.md).
available through the UI. You can use them by creating a new file,
choosing a template that suits your application, and adjusting it
to your needs:
![Use a YAML template](img/add_file_template_11_10.png)
While building your `.gitlab-ci.yml`, you can use the [CI/CD configuration visualization](pipeline_editor/index.md#visualize-ci-configuration) to facilitate your writing experience.
For a broader overview, see the [CI/CD getting started](quick_start/index.md) guide.
After you're familiar with how GitLab CI/CD works, see the
[`.gitlab-ci.yml` full reference](yaml/README.md)
for all the attributes you can set and use.
GitLab CI/CD and [shared runners](runners/README.md#shared-runners) are enabled on GitLab.com and available for all users, limited only by the [pipeline quota](../user/gitlab_com/index.md#shared-runners).
## Concepts
GitLab CI/CD uses a number of concepts to describe and run your build and deploy.