The “Parent/Child” relationship, in AceProject terminology, refers to the relationship between a template project and a project that was created based on the template.
When a new project (the child) is created from a template (the parent), the new project is by default linked to the template. As long as a child remains linked to its parent, the child project’s structure (task group, task type, task status and task priority values) will remain identical to its parent’s. Whenever a structure change is applied to the parent, all child projects that are still linked to the parent inherit the changes.
A child project can only be linked to its parent when it is created (in the “New Project” page). It is not possible to link a project to a template at any later point in time.