Digital files cannot be downloaded to iOS devices (i.e., Apple products like your iPhone or iPad). You can use the link provided in your confirmation email or on the "My Downloadable Products" section of your account to play or read the digital file on your device, but Apple's operating system does not support file downloads. The best way to load one of these files onto your phone or tablet is:
Step 1: Use a laptop or desktop computer to download your purchased file.
Step 2: Move the file into the iTunes account on your computer.
Step 3: Plug your phone or tablet into your computer to update/sync it with your iTunes account.
Note: You can download files to Android devices. For a guide to do so, click here.