Make me understand this code

Question

This is type and no of argument based code
https://code.sololearn.com/co5gjhdkxJOL/?ref=app

#include <iostream>
#include<iomanip>
using namespace std;
void display(char);
void display(int);
void display(char, int);
void display(int,int);

int main() {
char ch = 'a';
int inum= 25, n= 7;
cout<<"character function"<<endl;
display (ch);
cout <<"integer function"<<endl;
display (n);
cout <<"char & int function"<<endl;
display ('*',inum);
cout<<"int int fnctn"<<endl;
display (inum ,n);
system("Pause");
return 0;
}
void display (char character)
{
for(int i=0; i<5;i++)
cout <<setw(2)<<character;
cout<<endl;
}
void display (char character , int n)
{
for(int i=0; i<5;i++)
cout <<setw(2)<<character;
cout<<endl;

}
void display (int num)
{
for(int i=0; i<5;i++)
cout <<setw(4)<<num*(i+1);
cout<<endl;
}
void display (int num , int n)
{
for(int i=0; i<5;i++)
cout <<setw(3)<<num*(i+1);
cout<<endl;

}

Answer 1

This code uses prototype function, every function should be fully decleared before using it, or using the prototype then declear it below.