Example: Using versioned actions
steps:
# Reference a specific commit
- uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3
*-> # Reference the major version of a release
- uses: actions/checkout@v4
# Reference a specific version
- uses: actions/[email protected]
# Reference a branch
- uses: actions/checkout@main
Reference:
https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax

Types of actions
Docker container actions. Docker containers package the environment with the GitHub Actions code. ...
JavaScript actions. JavaScript actions can run directly on a runner machine, and separate the action code from the environment used to run the code. ...
Composite Actions.
Note:
JavaScript actions
JavaScript actions can run directly on a runner machine, and separate the action code from the environment used to run the code. Using a JavaScript action simplifies the action code and executes faster than a Docker container action.
Reference:
https://docs.github.com/en/actions/concepts/workflows-and-actions/custom-actions

Reusable workflows versus composite actions
Reusable workflows and composite actions both help you avoid duplicating workflow content.
Whereas reusable workflows allow you to reuse an entire workflow, with multiple jobs and steps, composite actions combine multiple steps that you can then run within a job step, just like any other action.
A composite action allows you to bundle multiple steps into a single reusable action within a workflow. It is composed of multiple run steps or other actions and can be reused across workflows, making it the perfect choice for bundling a series of steps.
Reference:
https://docs.github.com/en/actions/concepts/workflows-and-actions/reusable-workflows

Workflow syntax for GitHub Actions
Example: Running an inline Python script
steps:
- name: Display the path
shell: python
run: |
import os
print(os.environ['PATH'])
Reference:
https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax