Declaration and Executable statement

[dartzxx]

I am having trouble identifying a declaration v an executable statement. I just started C++ 2 weeks ago and I'm not familiar with the language. In the code below which are declaration and executable statements and why are such a declaration and an executable statement?

// =============================================================================

int main (void)

{
double Average (double [], int);
double Deviation (double [], int);
bool Done (int);
void Input (double [], int &);
void Intro (void);
void Print (double [], int, double, double);
double mean, stddev, score [100];
int count;
Intro ();
count = 0;
Input (score, count);
mean = Average (score, count);
stddev = Deviation (score, count);
Print (score, count, mean, stddev);

return 0;
}


void Intro (void)

{
system ("cls");

PrintLine (5, 77, 2, '=', 'c');

cout << setw (55) << "AVERAGE and STANDARD DEVIATION";

SkipLine (2, 'c');

cout << setw (64) << "The scores are inputted from an input textfile.";

PrintLine (2, 77, 2, '=', 'c');

Pause ();

return;
}

[vlad from moscow]

Declarations declare names that will be used in the program.

[dartzxx]

so In this case

double Average (double [], int);
double Deviation (double [], int);
bool Done (int);
void Input (double [], int &);
void Intro (void);
void Print (double [], int, double, double);
double mean, stddev, score [100];
int count;

are the declaration?