FreeBSD jailThe jail mechanism is an implementation of FreeBSD's OS-level virtualisation that allows system administrators to partition a FreeBSD-derived computer system into several independent mini-systems called jails, all sharing the same kernel, with very little overhead. It is implemented through a system call, jail(2), as well as a userland utility, jail(8), plus, depending on the system, a number of other utilities.OS-level virtualizationOS-level virtualization is an operating system (OS) virtualization paradigm in which the kernel allows the existence of multiple isolated user space instances, including containers (LXC, Solaris Containers, AIX WPARs, HP-UX SRP Containers, Docker, Podman, Guix), zones (Solaris Containers), virtual private servers (OpenVZ), partitions, virtual environments (VEs), virtual kernels (DragonFly BSD), and jails (FreeBSD jail and chroot).
FreeBSDFree and open-source Unix-like operating systemOperating systemFreeBSD is a free and open-sourceUnix-likeoperating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable home-class hardware, and has since continuously been the most commonly used BSD-derived operating system.
Root directoryIn a computerfile system, and primarily used in the Unix and Unix-likeoperating systems, the root directory is the first or top-most directory in a hierarchy. It can be likened to the trunk of a tree, as the starting point where all branches originate from. The root file system is the file system contained on the same disk partition on which the root directory is located; it is the filesystem on top of which all other file systems are mounted as the system boots up.
Operating systemAn operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources.
Shell (computing)An operating systemshell is a computer program that provides relatively broad and direct access to the system on which it runs. The term shell refers to how it is a relatively thin layer around an operating system. Most shells are command-line interface (CLI) programs. Some graphical user interfaces (GUI) also include shells.
System callIn computing, a system call (syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, accessing a hard disk drive or accessing the device's camera), creation and execution of new processes, and communication with integral kernel services such as process scheduling.
UnixUnix ( , YOO-niks; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, the development of which started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
Unix-likeA Unix-likeoperating system (sometimes referred to as a UN*X,*nix or *NIX) is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell.Command-line interfaceA command-line interface (CLI), also known as a command-line shell, is a means of interacting with software via commands – each formatted as a line of text. The concept of interacting with a computer via text evolved over two decades, transitioning from physical hardware to sophisticated software. Before the CLI, computers were programmed using physical switches or punched cards. The shift toward a "command" style interaction began with the use of Teleprinters (Teletypes).Child processA child process (CP) in computing is a process created by another process (the parent process). This technique pertains to multitasking operating systems, and is sometimes called a subprocess or traditionally a subtask. There are two major procedures for creating a child process: the fork system call (preferred in Unix-like systems and the POSIX standard) and the spawn (preferred in the modern (NT) kernel of Microsoft Windows, as well as in some historical operating systems).Command (computing)In computing, a command is a high-level instruction received via an external interface that directs the behavior of a computer program. Commonly, commands are sent to a program via a command-line interface, a script, a network protocol, or as an event triggered in a graphical user interface. Many commands support arguments to specify input and to modify default behavior. Terminology and syntax varies but there are notable common approaches.*As an Amazon Associate I earn from qualifying purchases.