chroot is system call / binary file which can change root directory for application. If used with care it can act as security feature often known as application jail. Mostly used for privilege separation and testing & development.
Few UNIX like operating system takes this concept further and creates os level virtualization. For example, Containers in Solaris or jails in FreeBSD or security contexts in Linux-VServer / Linux FreeVPS etc.
BoF can have multiple meanings :
- BoF - Buffer Overflow, a type of exploit for certain software bugs
- BoF - beginning of file
- BoF - can be movie or video game

HTH