Synology
https://www.synology.com/en-global
Qnap
https://www.qnap.com
Build your own NAS with Raspberry Pi
https://magpi.raspberrypi.org/articles/build-a-raspberry-pi-nas
Use Open Media Vault
https://www.windowscentral.com/ how-build-raspberry-pi-powered-nas
https://www.openmediavault.org/
Free NAS
https://www.freenas.org