Here you can download the multi-device template:
What is multi-device design?
This template you downloaded has an InDesign multi-device design, which consists of a single design that is used for all smartphones and tablets.
The pages have a vertical screen format of 1000x1334px. It is a document format that can be viewed on devices with aspect ratio 4: 3 or 16: 9.
This page size will allow us to make a unique design compatible with any screen resolution (iPhone, iPad, Android Smartphone and Android Tablet).
The guides in the document mark the area you see on all mobile devices. The space outside the guides will only be seen on some specific devices, such as the iPad and some Android tablets. Therefore, it is advisable to insert within those guides all the content that we want to be seen safely in any device.
Only parts of the elements that can be neglected at the visual level will be left out of the guides and will not conflict with the interactivity and understanding of the application, such as the sides of a photograph that acts as a page background or parts of graphics Present in the layout that have no significance.
In the following image, the yellow shaded area is the area within the guides. That area is the one that looks perfectly in any device.