What is the difference between Issue Links = child(ren) and Child Issues?

[Tracy Langston x2472]

[Nic Brough -Adaptavist-]

Your "chil(ren)" is an issue link type that has been added by an administrator.  The issue is not a child of the parent issue because of this link, it is a link, not a structure.

In the "child issues", the child issue is a structural child (sub-task) of the parent.

[Matt Doar]

Interestingly, I found out that you can add remote links to an issue using the REST API and in doing so appear to create your own "link type", such as "child(ren)".

However the link type is not added to those available. It's just text in an issue. I used this as part of a GitHub Jira integration we wrote. So it is possible that some plugin added the remote link in the issue without adding a link type named "child(ren)"