This type of meringue is made by beating egg whites until foamy, then slowly beating in granulated sugar. This method can make both soft and hard meringue, depending on how much sugar you add to the egg whites.
Italian meringue is made by heating up sugar and water to form a 220°F (104°C) sugar syrup. Then, while the egg whites are whipping in a stand mixer, the hot sugar syrup is slowly poured down the side of the mixing bowl. Allow the eggs to continue whipping to stiff peaks.
This method combines egg whites and granulated sugar in a bowl, then heats the mixture over a double boiler (bain marie) until the temperature reaches approximately 170°F (38°C). Then, the heated egg white mixture is whipped until stiff peaks have formed.