A boot environment (BE) is a ZFS file system that is designated for booting. A boot environment is essentially a bootable instance of the Oracle Solaris OS image, plus any other software packages that are installed into that image. You can maintain multiple boot environments on a single system. Each boot environment can have different OS versions installed. When you install Oracle Solaris, a new boot environment is automatically created during the installation.
For more information, see the beadm(8) man page as well as Creating and Administering Oracle Solaris 11.4 Boot Environments.
Multiple bootable datasets or root file systems can exist in a pool. In that pool, the default root file system is identified by the pool' s bootfs property. However, the zfs-bootfs command enables you to specify any bootable dataset to use. See the boot(8) man page.