NetBSD consists of a core base system and any third-party software you install
on top. The NetBSD base system can be upgraded in numerous ways, including
booting a new installer image, using the sysupgrade tool, or building from
source. For more information, see
[the NetBSD guide](//www.netbsd.org/docs/guide/en/chap-upgrading.html#using-sysupgrade).

NetBSD uses [pkgsrc](//www.pkgsrc.org) for managing third-party software. The instructions
for [upgrading pkgsrc packages](//www.NetBSD.org/docs/pkgsrc/using.html#using-pkg)
have moved to the pkgsrc guide.