Differentiate between a run time error and syntax error ?

Answer 1

Simple explanation:
syntax errors occur when the compilers finds errors in your syntax. (before the code even ran at all)
runtime errors occur when your code is already running

Answer 2

This would cause a syntax error:

#include <iostream

using std;

int main (
cout >> “Hello World’::std
)

This would cause a runtime error:

#include <iostream>

using namespace std;

int main() {
int * p = new int;
*p = 27;
cout << *p;

//now pointing to nothing
delete p;

//nullptr exception
cout << *p;
}