Inheritance Explanation

[Learned]

I got this code online but I am having problem understanding it:

#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>
using namespace std;

class Parent
{
public:
	virtual void action( const char how )  //....Line 1
	{ 
		this->action( &how ); 
	}
	virtual void action( const char * how ) = 0;
};

class Son : public Parent
{
public:
	using Parent::action; //....Line 2
	void action( const char * how )
	{
		cout<<"Action:"<<*how<<endl; }
};

int main()
{
	Son s;
	s.action( 'a' );


	system("pause");
	return 0;
}

From my previous understanding of inheritance function defined by Line 1 is redundant.
(1) Why do we need it, since if I delete it, there is an error?

(2) Why do we need the Line 2?

I have walked through the debugger but I do not understand the logic of code.