Question

I know the diff between struct and struct with typedef keyword in front. The reference is this: typedef struct vs struct definitions

struct myStruct{
    int one;
    int two;
};

vs

typedef struct{
    int one;
    int two;
}myStruct;

But what is the diff between this two types:

struct point {
   int x;
   int y;
};

vs

struct point {
   int x;
   int y;
} my_point;

One more:

    typedef struct set_t{    
      int count;
      void **values;
   } *SetRef;

what is this type?

Answer 1

struct point { int x; int y; };

This declares a new type struct point with two int members x and y.

struct point { int x; int y; } my_point;

This also declares a new type struct point with two int members x and y and this declares an object my_point of type struct point.