What does it mean when we write for example *pi=&a ????

Answer 1

Probably p is a pointer to pointer variable

int i= 1;
int i2= 2;
int* a= &i;
int* b= &i2;
int** p= &b;
*p= &a;

assign to "p" the adress of "a" pointer

Answer 2

*p is a pointer variable.
*p points to the memory address of variable 'a'.

*pi is dereferencing a pointer.
You might wanna revise pointers tutorial.

Answer 3

thank you💪