Hey everyone
It has been quite a while since i used a HTC device. HTC one m8 was my last HTC device exactly one year ago.
So I received my m9 today and I have some questions

First what is this download mode ?
Back in m8 (4.4.4) times there was this one bootloader with fastboot mode and options to boot into recovery etc.
For RUU's and firmwares there was this fastboot oem rebootRUU

Can someone explain this change/addition of download mode to me ? I think it's the replacement for fastboot mode maybe
I haven't tried rooting or anything till now.

Second

I only have 16 GB of free space available
ES File explorer says I have used 6.10 GBs of 22 gigs of usable internal storage.
Attachment 3316290

But I only have 2.41 Gb worth of data on the device

Attachment 3316291

Attachment 3316293

Any help regarding this will be really appreciated
And BTW I only have 5-6 applications installed other than what the shipped with

Snapchat
Whatsapp
Facebook Messenger
Twitter
ES file explorer
Asphalt8
XDA

With asphalt 8 being the only large app


Sent from my HTC One M9 using XDA mobile app

Attached Thumbnails