about pointer structure

[Aziz as]

Hello all
i am kinda confused about some segments of code that involve structures
what does it mean if a programmer writes the following
struct linked
{
int x ;
int y ;
string na ;
linked * some ; /*What does that specific line of code mean ?

}
also
struct linked
{
int x ;
int y ;
string na ;
linked some ; /*What does that specific line of code mean ?

}
please explain the difference between

[Bdanielz]

I would watch the first 3 videos of this series.
https://www.youtube.com/watch?v=Ps8jOj7diA0

[tcs]

linked *some; References another struct of type linked.

linked some; Is another object of type linked as one attribute of struct linked. This line would never compile, because 'linked' isn't completely defined at this time. And it cannot be defined because it would result in an endless recursive defined type:

struct linked
{
    int x;
    int y; 
    string na;
    struct linked
    {
        int x;
        int y; 
        string na;
        struct linked
        {
            int x;
            int y; 
            string na;
            // ....
        } some;
    } some;
}