Isomaltose (as shown below), like maltose, is also comprised of two glucose units. Contrast the two. (Note: The image shown below is isomaltose.)

Isomaltose has a β(1→4) linkage, while maltose has an α(1→5) linkage.

Isomaltose has an α(1→4) linkage, while maltose has an α(1→5) linkage.

Isomaltose has an α(1→6) linkage, while maltose has an α(1→4) linkage.

Isomaltose is a non-reducing sugar, while maltose is a reducing sugar.