what is the difference between pure virtual function and virtual function

#include <iostream>
#include <vector>

class Account
{
public:
  
	virtual void PrintBalance()
	{
		std::cout<<"Base"<<std::endl;
	}
};

class SavingAccount
    : public Account
{
public:
   void PrintBalance()
   {
	   std::cout<<"SavingAccount"<<std::endl;
   }
};

class CurrentAccount : public Account
{
	public:
   void PrintBalance()
   {
	   std::cout<<"CurrentAccount"<<std::endl;
   }

};

int main()
{
	Account *pAccount=NULL;
	SavingAccount objsavingAccount;
	CurrentAccount objcurrentAccount;
	pAccount = &objsavingAccount;
	pAccount ->PrintBalance();

	pAccount = &objcurrentAccount;
	pAccount ->PrintBalance();

    return 0;
}

OutPut:

SavingAccount
CurrentAccount