What does this statement do exactly

        if (dt.Rows[0][0].ToString() == "1")
        {
            this.Hide();

            Game GG = new Game();
            GG.Show();
        }
        else // else it will display this error
        {
            MessageBox.Show("Please enter the correct login details");
        }
    }

This is an if statement I am using for my game I am creating in c#. I'm trying to write internal commentary so I can describe each function properly and have a better understanding of the language. any help would be appreciated, Its just the top line i'm unsure about.