Alright so heres the program and works absolutely right

#include <iostream>

using namespace std;

template <typename T>
void Swap(T &a , T &b);

int main(){

    int i = 10;
    int j = 20;

    cout<<"i, j = " << i <<" , " <<j<<endl;
    Swap(i,j);
    cout<<"i, j = " << i <<" , " <<j<<endl;


}
template <typename T>
void Swap(T &a , T &b){
    T temp;
    temp = a ;
    a = b;
    b= temp;
}

but when I change the function's name from Swap to swap it generates an error saying

error: call of overloaded 'swap(int&, int&)' is ambiguous| note: candidates are: void swap(T&, T&) [with T = int]| ||=== Build finished: 1 errors, 0 warnings ===|

what happened is it a rule to start functions using templates to start with a capital letter ?