> For the complete documentation index, see [llms.txt](https://docs.work-relay.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.work-relay.com/processes/working-with-processes/interprocess-communication.md).

# Interprocess communication

Work-Relay provides a number of ways that processes can communicate amongst each other:

* **Through a Start Sub-Process action**

  For a hierarchical assembly of processes, a step in one process can trigger the start of another process. In this case, the triggered process (the sub-process) functions as an extension of the parent process and automatically has access to the parent process data.
* **Through the database layer**

  Disparate processes can communicate with one another via updates to the database.
* **Through step status**

  A step in one process can query the status of a step in any other process (started, completed, etc.). The status can be used by the step in its start conditions and rules.

Triggering a linked process versus call a sub-process:

A sub-process is triggered by a predefined action in a process. A linked process is triggered as a result of the status or other conditions that are outside the process (i.e. not predefined).