data classes and abstraction

i have doubts regarding the use of classes.please explain to me with an example.

Code:

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class POSITION
{
  public:
      POSITION();
      POSITION(int X, int Y);
      int GetX();
      int GetY();
      void SetX(int X);
      void SetY(int Y);
      void SetPosition(int X, int Y);
  private:
      int Xpos;
      int Ypos;
};

int main()
{
  POSITION PlayerPosition(120, 450);
  POSITION EnemyPosition(200, 180);
  ...
  return 0;
}

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