What’s the difference between include_tasks and import_tasks?

There’s quite a bit about this topic in the documentation:

• Includes vs. Imports
• Dynamic vs. Static

The main difference is:

All import* statements are pre-processed at the time playbooks are parsed.
All include* statements are processed as they encountered during the execution of the playbook.

So import is static, include is dynamic.

From my experience, you should use import when you deal with logical “units”. For example, separate long list of tasks into subtask files:

main.yml:

- import_tasks: prepare_filesystem.yml
- import_tasks: install_prerequisites.yml
- import_tasks: install_application.yml

But you would use include to deal with different workflows and take decisions based on some dynamically gathered facts:

install_prerequisites:

- include_tasks: prerequisites_{{ ansible_os_family | lower }}.yml