NetServer is the IBM software that's used for Windows networking.. . .
There's also QNTC, which allows IBM i to connect to other windows. . .
machines on the network.
Anyway, since Windows Networking uses a different form of encryption, et
al, from what IBM uses for it's passwords, when you set/change your
password, under the covers it will encrypt it according to the NetServer
style and save it as a "net server password" (in addition to the normal
encryption and storage used by IBM i itself.)
Certain password levels delete the netserver passwords for security