What kind of things that can be done using a NAS that cannot be done on an external USB enclosure? I mainly plan to use for backup of files from different comptuters/OS and file sharing.
It is its own little PC/server.
Simultaneous access from multiple systems. Windows, Linux, Android, Apple
Direct recording of my house surveillance cameras
Automated backups. With an external connected to
this PC, that requires
this PC to be on all the time.
Multiple users, with their own 'Home' space
Easy backups to other devices. Can sync to another NAS, across the country.
Plex server
VM server
Access from outside your LAN
Dedicated hardware RAID, if you're into that
Multiple dev tools
etc, etc, etc
QNAP designs and delivers high-quality network attached storage (NAS) and professional network video recorder (NVR) solutions to users from home, SOHO to small, medium businesses.
www.qnap.com
But if an external enclosure connected to your PC works for you, then that is all you need.