The user end point in Stack exhange API V.2.3, What modified filter in sort field consists of? It is unclear from the api docs https://api.stackexchange.com/docs/users

1. Is modified date includes any change triggered by system or user (change in user details or change in reputation by the system)?
2. Does it includes only the user made changes like details change or something?
3. Does it includes only the System triggered changes like changes in reputation, badge count etc?
4. Does it includes any changes in user profiles?

More precisely, I am interested to know whether modified date includes system triggered changes (reputation change, badge count etc) or not?