My friends were having discussion on nested lists of objects in LINQ and when I asked what does that mean, they laughed :(

Can anyone here tell what is nested list. is it same like list inside list? Thank you to all who help me

Is this NestedList?

```
public class X
{
public Y[] y { get; set; }   
}

public class Y
{
int id { get; set; }
}

```