What does the "parent"column in sys_ui_list table mean?

[prasanna11]

the sys_ui_list records of same view (such as default ) of same table (such as default list views of incident) have a column called "parent" which is normally filled with data such as "change_request" or "incident" or empty .

What do these mean and what is their purpose?

[sushant007]

that tells you the incident you see is child of change request or incident or anything.

basically one the change request you will be able to see the incident in related list as child