Phone storage combines both the app storage, where apps, email, data, and text messages are stored, and the file storage, where photos, videos, and music files are kept.
Use a storage card for storing more files. You can also set apps such as
Camera to store directly to the card.
When you plug in an external USB storage device —such as a USB flash drive or an SD card reader— you can open certain files such as photos, videos, music, and documents that are stored on the external device.
You need a special cable to connect a USB storage device to your phone.
HTC Desire 820G+ dual sim supports up to 64 GB of USB storage devices. Portable hard drives are not supported.