Glossary
This glossary collects the technical terms covered in this book, arranged in the order of their first appearance in the main text.
操作系统
/
System software that manages computer hardware and software resources, provides common services for computer programs, and serves as the interface between users and computer hardware
分时系统
/
An operating system that allows multiple users to simultaneously use a single computer by dividing CPU time into time slices and serving each user in turn
内核
/
The core part of an operating system that resides in memory, responsible for managing the system's processes, memory, device drivers, file systems, and networking
微内核
/
An operating system kernel architecture that runs only the most essential services in kernel mode, with other services implemented as user-space processes
宏内核
/
An operating system kernel architecture that integrates all core services such as process management, memory management, file systems, and device drivers within the kernel space. Also known as a monolithic kernel
UNIX 哲学
/
A software engineering methodology system derived from the development practices of the UNIX operating system, emphasizing small and refined design, each program focusing on a single task, prototyping first, and prioritizing portability over efficiency as core design principles
可移植性
/
The ease with which software can be transferred from one hardware platform or operating system environment to another and still function properly
自由软件
/
Software that grants users the freedom to run, copy, distribute, study, modify, and improve it
copyleft
著佐权
A licensing approach, similar to GPL terms, that imposes copyright constraints on derivative works, such as requiring source code to be made public
开源软件
/
Software whose source code is publicly available and allows users to freely use, modify, and distribute it
专有软件
/
Proprietary Software, a type of non-free software, also known as private software. Software that users are not free to use, modify, or distribute; most commercial software falls into this category
许可证
/
License, a legal agreement that authorizes others to use, modify, or distribute software
GNU
/
GNU's Not Unix, an operating system project initiated by the Free Software Foundation
GPL
/
GNU General Public License, a strong copyleft license
BSD 许可证
/
A permissive open source license that allows commercial use and closed-source derivatives
BSD
伯克利软件发行版
Berkeley Software Distribution, an operating system distribution based on AT&T UNIX, improved and extended by the University of California, Berkeley, and subsequently developed by the Computer Systems Research Group (CSRG), representing an important branch in the technical evolution of UNIX
类 UNIX
/
Unix-like, operating systems that behave similarly to UNIX but are not necessarily certified under the SUS
发行版
/
Distribution, a complete operating system packaged and released based on a kernel and its accompanying software collection
内核模块
/
A code segment that can be dynamically loaded into or unloaded from the kernel at runtime, extending kernel functionality without requiring kernel recompilation
Base System
基本系统
The combination of the kernel and user space (known as world in FreeBSD), i.e., all components from the src source tree
用户空间
/
Userland / Userspace, the runtime environment of the operating system outside the kernel, where applications execute
ABI
应用程序二进制接口
Application Binary Interface, the binary interface standard between applications and the operating system
RELEASE
稳定版
An official release version suitable for production environments
STABLE
/
FreeBSD's stable development branch, providing ABI stability guarantees while still under development
CURRENT
/
FreeBSD's main development branch, corresponding to the head or main branch in typical projects, containing the latest code changes but potentially unstable
MFC
合并自 CURRENT
Merge From CURRENT, the process in FreeBSD development of merging changes from the CURRENT branch into stable branches
Jail
/
An operating system-level isolation technology developed on the basis of Chroot, achieving lightweight virtualization through isolation mechanisms at the file system, process, network, and user dimensions; one of the important early practices of modern container technology
ZFS
/
Originally an abbreviation for Zettabyte File System, later no longer officially treated as an acronym. An advanced storage system integrating a file system and logical volume manager, employing a copy-on-write transaction model with powerful data integrity protection mechanisms, efficient data compression, and a scalable storage architecture
OpenZFS
/
The open source community version of ZFS, unifying the open source development of ZFS
bhyve
/
BSD Hypervisor, FreeBSD's built-in hypervisor
DTrace
/
Dynamic Tracing, a dynamic tracing framework originally developed by Sun Microsystems and first released with Solaris 10, usable for real-time debugging of kernel and application issues in production systems
Capsicum
/
A lightweight operating system capability and sandbox framework for application sandboxing
PF
包过滤器
Packet Filter, firewall software originating from OpenBSD, available as an optional firewall in FreeBSD, supporting features such as ALTQ traffic shaping
Netgraph
/
FreeBSD's network graph framework, providing graph-based abstraction and programmable interconnection of kernel-level network nodes
GEOM
/
FreeBSD's disk I/O request transformation framework, providing features such as disk partitioning, encryption, and mirroring
UFS
Unix 文件系统
Unix File System, FreeBSD's traditional file system
Port
/
A source code package for a single software in the FreeBSD system, containing the configuration files and scripts needed to compile and install that software
Ports
/
FreeBSD's software package management system, containing the collection of all Ports, used to compile and install software from source code
Ports Collection
/
The complete collection of the Ports system, including software category directories, build tools, and dependency management mechanisms
pkg
/
FreeBSD's binary package manager, used to install, update, and manage pre-compiled software packages; formerly known as pkgng
PkgBase
/
FreeBSD's base system package management scheme, using the pkg package manager to implement updates for user space and the kernel, available as a Technology Preview starting from FreeBSD 15.0
freebsd-update
/
FreeBSD base system update tool, used to fetch security updates and perform system version upgrades
Poudriere
/
A FreeBSD tool that tests Ports and builds FreeBSD package images through Jail environments
安全启动
/
Secure Boot, a security mechanism based on UEFI firmware that verifies the integrity of boot loaders and operating system kernels through digital signatures
Linuxism
/
The phenomenon where software overly depends on Linux-specific features, making it difficult to port to other Unix-like operating systems
POLA
最小惊讶原则
Principle of Least Astonishment, a design principle stating that designs must conform to users' habits, expectations, and cognitive abilities
UNIX
/
An operating system originally developed at AT&T Bell Laboratories, now a standard specification and legal trademark
Single UNIX Specification
单一 UNIX 规范
SUS, the standard specification for the UNIX operating system
CDDL
通用开发与发行许可
Common Development and Distribution License, an open source license created by Sun Microsystems for OpenSolaris, adopted by projects such as ZFS, allowing commercial use and modification
TCP/IP
传输控制协议/网际协议
Transmission Control Protocol/Internet Protocol, the foundational protocol suite of the Internet
校验和
/
Checksum, a fixed-length value obtained by performing a specific algorithm on a data sequence, used to detect whether errors have occurred during data transmission or storage
哈希函数
/
Hash Function, a function that maps data of arbitrary length to a fixed-length value, used for data integrity verification and digital signatures
内核错误（Kernel Panic）
/
Kernel Panic, a self-protection mechanism invoked when the operating system kernel encounters an unrecoverable fatal error; the system stops running and displays an error message
分发文件
/
Distribution Set, a collection of compressed packages in the FreeBSD installation media divided by function, such as base, kernel, src, lib32, etc.
无线管制域
/
Regulatory Domain, a legally defined region specifying the frequency, power, and other parameters for wireless device usage in each country or region
UEFI
统一可扩展固件接口
Unified Extensible Firmware Interface, the firmware interface standard for modern computers
BIOS
基本输入输出系统
Basic Input/Output System, the traditional firmware interface standard for computers
GPT
全局唯一标识分区表
GUID Partition Table, a disk partition table standard
MBR
主引导记录
Master Boot Record, the traditional disk partition table standard
引导加载程序
/
Bootloader, a program executed when a computer starts, responsible for initializing hardware devices and loading the operating system kernel into memory for execution
分区
/
Partition, the operation of dividing a physical disk into several logical storage areas
交换
/
Swap, the mechanism by which the operating system writes temporarily unused memory pages to a disk swap area to free physical memory
挂载
/
Mount, the operation of associating a file system with a directory in the directory tree, making its contents accessible
DHCP
动态主机配置协议
Dynamic Host Configuration Protocol, a protocol that automatically assigns IP addresses and other network configurations to hosts
SSH
安全外壳协议
Secure Shell, a protocol for secure remote login
DNS
域名系统
Domain Name System, a distributed naming system that maps domain names to IP addresses
虚拟化
/
Virtualization, technology that abstracts computer physical resources into logical resources, enabling multiple operating systems or applications to run independently on the same physical hardware
虚拟机
/
Virtual Machine, a complete computer system simulated through virtualization technology
VirtIO
/
A virtualization I/O framework providing standardized high-performance I/O interfaces for virtual machines
串口控制台
/
Serial Console, an interface for system management and debugging through a serial port
Chroot
/
Change Root, an operation that changes the root directory of a process and its child processes to another location in the file system
TTY
/
Teletypewriter, a teletypewriter, extended to refer to text terminal devices
虚拟控制台
/
Virtual Console, multiple independent logical terminals simulated on a physical terminal
Shell
/
A program in the operating system that provides a user interface, serving as the interface between the user and the kernel, responsible for interpreting and executing user-entered commands
命令解释器
/
Command Interpreter, a program that receives user-entered commands and translates them into instructions executable by the operating system
环境变量
/
Environment Variable, named value pairs in the operating system used to store system runtime environment and user configuration information, readable and usable by processes
POSIX
/
Portable Operating System Interface, an operating system standard developed by IEEE and The Open Group
进程
/
Process, a single execution instance of a program on a computer, the basic unit of resource allocation and scheduling in the operating system
守护进程
/
Daemon, a system process running in the background, not associated with any controlling terminal, typically responsible for listening for network requests or performing system maintenance tasks
信号
/
Signal, a software interrupt mechanism in the operating system used to notify a process that an event has occurred
文件系统
/
File System, the software component in the operating system responsible for managing and accessing file information
符号链接
/
Symbolic Link, a special type of file whose content is a path name pointing to another file or directory. Also known as a soft link
硬链接
/
Hard Link, multiple directory entries pointing to the same inode in a file system, sharing the same data blocks as the original file
权限提升
/
Privilege Escalation, the act of obtaining higher privileges beyond the authorized scope
SUID
设置用户 ID
Set User ID, a file permission bit that temporarily grants the user executing the file the permissions of the file owner
SGID
设置组 ID
Set Group ID, a file permission bit that temporarily grants the user executing the file the permissions of the file's group owner
设备文件
/
Device File, a special file in the operating system that represents a hardware device or virtual device
procfs
/
Process File System, a file system that presents kernel process information in a file system format (FreeBSD does not mount it by default; manual mount_procfs(8) is required)
devfs
/
Device File System, a file system that automatically manages device nodes in the /dev directory
fdescfs
/
File Descriptor File System, a file system that provides file system access to process file descriptors
伪终端
/
Pseudo-Terminal, a terminal device simulated in software, used for remote login and terminal emulation in window systems
PAM
可插拔认证模块
Pluggable Authentication Modules, a flexible system authentication framework originally developed by Sun Microsystems in 1995
Kerberos
/
A network authentication protocol that uses a Key Distribution Center (KDC) and ticket mechanism to achieve secure identity verification
NIS
网络信息服务
Network Information Service, a system developed by Sun Microsystems for centrally managing user and host information on a network, formerly known as Yellow Pages (YP)
NTP
网络时间协议
Network Time Protocol, a protocol used to synchronize clocks across nodes in a computer network
syslog
/
A system logging protocol and tool used for recording system messages and events
OpenBSM
/
Open Basic Security Module, FreeBSD's security auditing system
审计
/
Audit, the process of recording, examining, and analyzing system security-related events
inetd
互联网超级服务器
Internet Super Server, a daemon that uniformly manages multiple network services
IPFW
/
ipfirewall, FreeBSD's built-in firewall system, employing first-match rules
IPF
/
IPFilter, a firewall software available as an optional firewall component in FreeBSD
ALTQ
交替队列
Alternate Queuing, a traffic shaping framework developed by Kenjiro Cho, first released in March 1997, later incorporated into the KAME project, integrated with the PF firewall to provide queue management and traffic shaping functionality
二进制包
/
Binary Package, a pre-compiled software package that can be installed directly without building from source code
镜像站
/
Mirror Site, a server that synchronizes and replicates official software repositories or distribution files, providing faster local download speeds
源代码
/
Source Code, the original text of a computer program written by programmers, which must be compiled or interpreted before execution
依赖
/
Dependency, a reference relationship between software where the normal operation of one software requires the presence of another
启动环境
/
Boot Environment, a bootable file system snapshot on ZFS that supports system version rollback
数据集
/
Dataset, a management unit in ZFS, similar to an independent partition in a traditional file system
存储池
/
Storage Pool / zpool, a storage space in ZFS composed of one or more virtual devices
快照
/
Snapshot, a read-only copy of a file system or storage system at a specific point in time
写时复制
/
Copy-on-Write (COW), an optimization strategy that copies data before writing modifications, ensuring data consistency
etcupdate
/
A FreeBSD tool used to merge configuration file changes after system upgrades
buildworld
/
One of the FreeBSD source code build processes, compiling the complete user space
buildkernel
/
One of the FreeBSD source code build processes, compiling the kernel
installworld
/
One of the FreeBSD source code build processes, installing the compiled user space
releng
/
Release Engineering, FreeBSD's release engineering branch
Linux 兼容层
/
A FreeBSD system feature that enables running Linux binary programs on FreeBSD, providing application compatibility
Linuxulator
/
The Linux system call translation layer in the FreeBSD kernel, implementing Linux binary compatibility
RISC-V
/
An open source instruction set architecture based on RISC principles, initiated by the University of California, Berkeley in 2010; FreeBSD supports hardware platforms with the RISC-V architecture
kqueue
/
FreeBSD's event notification interface, providing a more efficient and scalable event notification mechanism than select/poll
TrustedBSD
/
FreeBSD's security extension project, based on the POSIX.1e draft
W^X
写或执行互斥
Write XOR Execute, a security policy where memory pages cannot simultaneously have write and execute permissions
PIE
位置无关可执行程序
Position Independent Executable, a security mitigation technique where executables can be loaded at arbitrary addresses
ASLR
地址空间布局随机化
Address Space Layout Randomization, a security mitigation technique that increases attack difficulty by randomizing the memory layout of processes
DAC
自主访问控制
Discretionary Access Control, the standard Unix security model where resource owners can autonomously determine access permissions
ACL
访问控制列表
Access Control List, an object-centric access control mechanism that provides more granular control than traditional Unix permissions
CHERI
/
Capability Hardware Enhanced RISC Instructions, a CPU architecture extension developed by the University of Cambridge and SRI International, a project led by Robert N.M. Watson alongside Capsicum; CHERI was conceptually inspired by Capsicum, extending the capability model from software to hardware, but the two are independent projects, not derivative of each other
Container
容器
A lightweight operating system-level virtualization technology that achieves process isolation and resource control through isolation mechanisms and resource limits
NAT
网络地址转换
Network Address Translation, a technology that translates addresses in IP packet headers to another address
代理服务器
/
Proxy Server, a server that acts as an intermediary between clients and servers, forwarding requests and responses
防火墙
/
Firewall, a system that enforces access control policies between networks, protecting network security by allowing or denying packet transmission
ICMP
互联网控制报文协议
Internet Control Message Protocol, a protocol used to send control messages and error reports in IP networks
UDP
用户数据报协议
User Datagram Protocol, a connectionless transport layer protocol
TCP
传输控制协议
Transmission Control Protocol, a connection-oriented, reliable transport layer protocol
HTTP
超文本传输协议
HyperText Transfer Protocol, an application layer protocol that is the foundation of data communication on the World Wide Web
HTTPS
超文本传输安全协议
HyperText Transfer Protocol Secure, a protocol encrypted through TLS on top of HTTP
拥塞控制
/
Congestion Control, a mechanism in networks that prevents excessive data injection from causing network congestion
Wayland
/
A display server protocol designed to replace X11
显示服务器
/
Display Server, the core service program in a graphics system responsible for managing screen output and input devices
显示管理器
/
Display Manager, a program in a graphics system that provides a user login interface and manages session startup, such as GDM, SDDM, LightDM, etc.
合成器
/
Compositor, a component in a graphics system responsible for compositing the rendering results of multiple windows into the final screen image
X11
X 窗口系统
X Window System, a window system for graphical user interfaces
CDE
通用桌面环境
Common Desktop Environment, a classic UNIX desktop environment
驱动程序
/
Driver, interface software between the operating system and hardware devices, responsible for converting operating system requests into hardware-executable operations
人工智能
/
Artificial Intelligence, the discipline and technology field studying how to make computers simulate human intelligent behavior
OpenBSD
/
A security-focused BSD operating system forked from NetBSD by Theo de Raadt in 1995
NetBSD
/
A portability-focused BSD operating system founded in 1993
DragonFly BSD
/
A BSD operating system forked from FreeBSD 4.8 by Matthew Dillon in 2003
LLVM
/
LLVM is not an acronym (it once stood for Low Level Virtual Machine, but is no longer officially treated as one), referring to a collection of modular and reusable compiler and toolchain technology projects (see LLVM Project. LLVM FAQ[EB/OL]. [2026-04-16]. https://llvm.org/. This page is the LLVM official overview page)
编译程序
/
Compiler, a program that translates high-level programming language source code into machine code or intermediate code
解释程序
/
Interpreter, a program that reads and executes high-level programming language source code line by line
Clang
/
The C/C++ language frontend and tool infrastructure of the LLVM project
NFS
网络文件系统
Network File System, a distributed file system protocol
SMB
服务器消息块
Server Message Block, a protocol used for file sharing
交叉编译
/
Cross-compilation, the compilation process of producing executable code for another platform on one platform
设备树
/
Device Tree, a data structure describing hardware device information, used for hardware discovery in embedded systems
单板计算机
/
Single-Board Computer, a complete computer integrated on a single circuit board
固件
/
Firmware, software embedded in hardware devices that controls the basic operations of the device
运行级别
/
Runlevel, levels defining system running states in SysVinit systems
伪静态
/
URL Rewriting, a technology that maps dynamic URLs to static URLs through server-side rules
反向代理
/
Reverse Proxy, a proxy server that receives client requests, forwards them to backend servers, and returns the responses to the clients
时序数据库
/
Time Series Database, a database specifically designed for storing and querying time series data
ORDBMS
对象关系型数据库管理系统
Object-Relational Database Management System, a relational database that supports features such as objects, classes, and inheritance
NoSQL
/
Not Only SQL, a database management system that does not strictly follow the relational model
文档型数据库
/
Document-oriented Database, a database that stores and retrieves data in units of documents
SCRAM-SHA-256
/
Salted Challenge Response Authentication Mechanism, an authentication mechanism based on SHA-256
ACID
/
Atomicity, Consistency, Isolation, Durability, the four fundamental properties of database transactions: atomicity, consistency, isolation, and durability
SSL/TLS
安全套接层/传输层安全
Secure Sockets Layer / Transport Layer Security, protocols that provide security and data integrity for network communications
FastCGI
/
Fast Common Gateway Interface, an improved CGI protocol that handles requests through persistent processes to improve performance
JIT 编译程序
即时编译程序
Just-In-Time Compiler, a compiler that compiles bytecode into machine code while the program is running
Java Servlet
/
A server-side component on the Java platform for handling HTTP requests
SPICE
/
Simple Protocol for Independent Computing Environments, a remote display protocol
VNC
虚拟网络计算
Virtual Network Computing, a remote desktop protocol
RDP
远程桌面协议
Remote Desktop Protocol, a remote desktop protocol developed by Microsoft
FUSE
用户空间文件系统
Filesystem in Userspace, a framework that allows non-privileged users to create file systems in user space
autofs
/
Automatic File System, an automatic mount file system framework
fsck
/
File System Consistency Check, a file system consistency check and repair tool
GELI
/
FreeBSD's disk encryption framework
sysctl
/
System Control, the interface for reading and setting FreeBSD kernel runtime parameters
securelevel
/
Security level, FreeBSD's kernel security level mechanism; the higher the level, the stricter the restrictions
rctl
/
Resource Control, FreeBSD's resource limiting tool
mac_bsdextended
/
FreeBSD's Mandatory Access Control (MAC) policy module, providing firewall-like rule-based access control for file systems
devd
/
Device Daemon, FreeBSD's device status daemon that responds to hardware events
powerd
/
Power Daemon, FreeBSD's power management daemon
cron
/
The Unix system's scheduled task execution daemon, used to automatically execute tasks at predetermined times
DMA
/
① Direct Memory Access, a technology that allows devices to directly read and write system memory; ② DragonFly Mail Agent, incorporated into the FreeBSD base system in 2014 and replacing Sendmail as the default local mail transfer agent (not a full-featured MTA) starting from FreeBSD 14.0; the default MTA for FreeBSD 13 and earlier was Sendmail
mtree
/
FreeBSD's directory tree specification and verification tool
authpf
/
Authenticating Gateway User Shell, the authentication gateway shell for the PF firewall
Unbound
/
A validating recursive DNS server
Kyua
/
The automated testing framework adopted by the FreeBSD base system for running regression tests. Originally developed for the NetBSD project, later incorporated into the FreeBSD base system
内存盘
/
RAM Disk, a technology that simulates memory as a disk device, with data stored in memory and lost on power-off. FreeBSD provides RAM disk functionality through mdconfig and the md(4) driver. mfsBSD is a minimal FreeBSD distribution that runs from a RAM disk
GRUB
/
Grand Unified Bootloader, a universal multi-operating system boot loader
init
/
The initialization process with PID 1 in UNIX systems, responsible for post-boot initialization work
调试器
/
Debugger, a tool used to detect and locate program errors
版本控制
/
Version Control, the system and method for managing the change history of files or code
补丁
/
Patch, fix code provided for issues or functional defects discovered in software
网络协议
/
Network Protocol, a collection of rules, standards, or conventions established for data exchange in computer networks
端口
/
Port, a logical identifier used in network communication to distinguish different applications or services, with a value range of 0–65535
套接字
/
Socket, an endpoint of network communication, composed of an IP address and port number, serving as the interface between applications and the network
管道
/
Pipe, an interprocess communication mechanism that directly connects the output of one process to the input of another
中断
/
Interrupt, the process by which a CPU responds to an event occurring in the system, suspending the current program to execute an interrupt handler
线程
/
Thread, an execution unit within a process that shares the process's resources but has an independent execution flow
虚拟存储器
/
Virtual Memory, also known as virtual memory, a memory management technology provided by the operating system that combines physical memory with disk space to provide a contiguous address space for processes
高速缓存
/
Cache, high-speed memory located between the CPU and main memory, used to reduce memory access latency