Address of array - difference between having an ampersand and no ampersand

Question

I have a struct that looks like this:

struct packet {
  int a;
  char data[500];
};
typedef struct packet packet_t;

I\'m a little confused

Answer 1

That's because array decays to a pointer pointing to first element in the sequence. So, packet.data address location is same as &packet.data or &packet.data[0].