What are double layer Blu-ray disks?

Double-layer means that there are two layers of the disk in which the data is held. Nearly every DVD and Blu-Ray movie is double-layered. Sometimes when the player transitions from one layer to another, it can create a short pause. But the disc being double-layered is good, for that means it can hold up 2 times more data than a single layer. A double-layered Blu-Ray holds up to a maximum of 50 GB of data, which is 5 times more data storage than a double-layered DVD's maximum