Pre-U Edexcel Computer Science Glossary Mnemonics | Pre-U Edexcel 计算机：词汇术语速记指南

📚 Pre-U Edexcel Computer Science Glossary Mnemonics | Pre-U Edexcel 计算机：词汇术语速记指南

Mastering the core terminology of Pre-U Edexcel Computer Science is half the battle. This guide turns abstract terms into vivid mental images, acronyms, and bite‑sized stories that stick. Work through each section and you will walk into the exam with a well‑stocked mental library.

掌握 Pre-U Edexcel 计算机科学的核心术语，就等于赢了一半。这份指南把抽象词汇变成生动的脑海画面、首字母缩略词和短小精悍的故事，让记忆牢牢扎根。跟着每个小节过一遍，你将带着一座丰富的“词库”走进考场。

1. Computational Thinking Toolkit | 计算思维工具箱

Abstraction means stripping away unnecessary detail to focus on what matters. Picture a tube map: you see stations and connections, not real distances or building layouts. Decomposition is breaking a big problem into smaller, manageable parts — like tackling a jigsaw puzzle one corner at a time. Algorithmic thinking is the step‑by‑step logic you write before coding; imagine a cooking recipe that cannot skip an instruction.

抽象（Abstraction） 是指剥离不必要细节，聚焦关键信息。想象一下地铁路线图：你能看到车站和连接关系，但看不到真实距离或建筑布局。分解（Decomposition） 是把大问题拆成可控的小块——就像从角落开始拼一幅拼图。算法思维（Algorithmic thinking） 是写代码前的逐步逻辑；想象一本不能跳过任何步骤的菜谱。

2. Data Structures in a Nutshell | 数据结构速览

An array is a line of identical lockers, each with a number (index). You can instantly open locker 3, but inserting a new locker in the middle forces you to shift everything. A list is like a treasure hunt: each item holds a pointer to the next, so inserting is easy, but you must follow the chain to find item 5. A stack is a pile of plates — Last In, First Out (LIFO). Push adds a plate, pop removes the top one. A queue is a bus line — First In, First Out (FIFO). Enqueue joins the back, dequeue leaves the front.

数组（Array） 就像一排一模一样的储物柜，每个都有编号（索引）。你可以立刻打开3号柜，但要在中间插入一个新柜子，必须把所有后面的柜子都挪动。链表（List） 好比寻宝游戏：每件物品带有指向下一个的指针，插入很容易，但要找到第5件就必须沿着链条一个一个走。栈（Stack） 是一摞盘子——后进先出（LIFO）。Push 加一个盘子，Pop 拿走最上面的。队列（Queue） 是排队上车——先进先出（FIFO）。Enqueue 加入队尾，Dequeue 离开队首。

3. Sorting & Searching — Remember the Rhythm | 排序与搜索——记住节奏

Bubble sort “bubbles” the largest element to the end on each pass, like fizzy water lifting the biggest bubble slowly. Say “compare, swap, repeat” in your head. Merge sort divides the list in half, sorts each half, then merges: “divide, conquer, combine”. Linear search checks every item one by one — a detective checking every house in a street. Binary search needs a sorted list and splits the search space in half each time — flipping through a dictionary directly to the middle letter.

冒泡排序（Bubble sort） 每一趟都把最大的元素“冒”到最后，就像汽水里的气泡慢慢把最大的推上去。心里默念“比较、交换、重复”。归并排序（Merge sort） 把列表分成两半，各自排序再合并：“分割、征服、合并”。线性搜索（Linear search） 一个接一个检查每个元素——像侦探敲遍一条街的每户人家。二分搜索（Binary search） 要求有序列表，每次把搜索空间减半——就像翻词典直接翻到中间字母。

4. Programming Paradigms — Two Worlds | 编程范式——两个世界

Imperative programming tells the computer exactly how to do something step by step — you are the boss giving direct orders. Declarative programming says what you want, not how to get it — like ordering a pizza without describing the oven’s temperature. Think of SQL: you declare “SELECT name FROM students WHERE grade > 80” and the system figures out the path. Functional programming builds everything from pure functions that always return the same output for the same input, with no side effects — mathematical safety.

命令式编程（Imperative programming） 一步步告诉计算机怎么做——你是老板，下直接指令。声明式编程（Declarative programming） 只说你要什么，不说怎么实现——就像点一个披萨，不用描述烤箱温度。想想SQL：你声明“SELECT name FROM students WHERE grade > 80”，系统自己找出实现路径。函数式编程（Functional programming） 一切都用纯函数构建，相同输入必得相同输出，没有副作用——数学般的安全感。

5. OOP Pillars — The S.A.P. Memory Trick | 面向对象四大支柱——S.A.P. 记忆法

Remember the four pillars of Object‑Oriented Programming with S.A.P.I. — but we’ll twist it into a story: A Spy Adapts Polymorphically while Inheriting secrets. Actually the pillars are: Encapsulation (bundling data and methods, hiding inner state — a pill capsule protecting the medicine inside), Inheritance (child class reuses parent attributes — a son inheriting a family business), Polymorphism (same method name, different behaviour — a “play” button that works for music, video, or game), and Abstraction (showing only essential features — a car dashboard hiding the engine complexity).

用S.A.P.I.记住面向对象编程的四大支柱——再编个故事：Spy（间谍）Adapts（适应）Polymorphically（多态地）同时Inheriting（继承）秘密。实际上支柱是：封装（Encapsulation）——把数据和方法捆绑，隐藏内部状态，像胶囊保护里面的药；继承（Inheritance）——子类复用父类属性，像儿子继承家业；多态（Polymorphism）——相同方法名，不同行为，比如一个“播放”按钮对音乐、视频、游戏都有不同反应；抽象（Abstraction）——只展示必要特性，就像汽车仪表盘隐藏了发动机的复杂。

6. Database Terminology — The ACID Test | 数据库术语——ACID 准则

A transaction must pass the ACID test: Atomicity (all or nothing — a marriage ceremony: the whole thing happens, or it doesn’t count), Consistency (rules still hold after the transaction — a bank transfer must keep total money the same), Isolation (concurrent transactions don’t interfere — two cashiers selling the last ticket will not both succeed), Durability (once committed, changes survive a power cut — carved in stone). Also remember Normalisation: organising data to reduce redundancy, like making sure each fact is stored just once.

事务必须通过ACID测试：原子性（Atomicity）——要么全做，要么全不做，像婚礼：整个仪式完成才算数；一致性（Consistency）——事务后规则仍成立，银行转账保持总金额不变；隔离性（Isolation）——并发事务互不干扰，两个售票员卖最后一张票，不可能都成功；持久性（Durability）——一旦提交，即使断电改变也在，像刻在石头上。同时记住规范化（Normalisation）：组织数据减少冗余，像确保每个事实只存一次。

7. Networking Like a Postal Service | 像邮政系统一样理解网络

Think of TCP as a registered mail with a tracking number: every packet is acknowledged, lost ones are resent — reliable. UDP is throwing postcards: fast, but if a postcard gets lost, no one resends it. IP address is the house number; MAC address is the physical house location that never changes. The DNS is a phonebook converting domain names to IP addresses. HTTP/HTTPS are the language of requests for web pages; the ‘S’ locks the conversation with encryption.

把TCP想象成有追踪码的挂号信：每个包都被确认，丢失会重发——可靠。UDP就像扔明信片：快，但如果有明信片丢了，没人会重发。IP地址是门牌号；MAC地址是房子不变的物理位置。DNS是电话本，把域名转成IP。HTTP/HTTPS是请求网页的语言；‘S’用加密锁住对话。

8. Logic Gates — Light Switch Logic | 逻辑门——电灯开关逻辑

AND gate: both inputs must be 1 for output 1 — a door that opens only when two keys are turned together. OR gate: at least one input 1 gives output 1 — a hallway light controlled by two switches; flipping either one turns it on. NOT gate is an inverter — 1 becomes 0, like a “Do not enter” sign reversing permission. Use NAND and NOR as the universal gates: any circuit can be built from NAND alone or NOR alone. Build a truth table for every gate to see the pattern instantly.

与门（AND）：两个输入都为1，输出才为1——一扇需要两把钥匙同时转动才能打开的门。或门（OR）：至少一个输入为1，输出就为1——由两个开关控制的走廊灯；扳动任何一个都会亮。非门（NOT）是反相器——1变0，就像“禁止进入”标志扭转许可。与非门（NAND）和或非门（NOR）是通用门：任何电路都能只用NAND或只用NOR实现。为每个门画真值表，一眼就能看出模式。

9. System Software — The Invisible Helpers | 系统软件——看不见的帮手

The operating system is a camp manager: it handles memory, processes, file management, and I/O. The BIOS/UEFI wakes up the hardware at boot — the rooster that starts the day. A compiler translates whole high‑level code into machine code once — a full book translation. An interpreter translates and runs line by line — a personal interpreter walking with you, translating as you speak. A linker stitches compiled pieces and libraries into a single executable, like putting book chapters together.

操作系统就像营地管理者：处理内存、进程、文件管理和输入输出。BIOS/UEFI在启动时唤醒硬件——是清晨打鸣的公鸡。编译器一次性地把整个高级代码翻译成机器码——整本书翻译。解释器逐行翻译并执行——像边走边翻译的随身口译员。链接器把编译好的模块和库缝合成一个可执行文件，就像把书的章节装订在一起。

10. Number Bases — Paint by Digits | 数制——数字作画

Denary is base 10, our everyday digits 0‑9 — ten fingers. Binary is base 2, 0 and 1 — the language of on/off switches. Hexadecimal is base 16, using 0‑9 then A‑F — compact colour codes like #FF5733. To convert binary to hex, group bits in fours from the right: 1101 0110 becomes D6. Remember the powers: from rightmost, binary positions are 1, 2, 4, 8, 16… (2ⁿ). Two’s complement stores negative numbers by flipping all bits and adding one; the most significant bit becomes the sign flag.

十进制是基数为10，我们日常用的0‑9——十根手指。二进制基数为2，只有0和1——开关的语言。十六进制基数为16，用0‑9然后A‑F——紧凑的颜色代码如#FF5733。二进制转十六进制时，从右开始四位一组：1101 0110变成D6。记住权重：最右边开始，二进制位的值是1, 2, 4, 8, 16…（2ⁿ）。二进制补码通过翻转所有位并加一来存储负数；最高位成为符号标志。

11. Security — The CIA Triad Forever | 安全——永记CIA三元组

Security revolves around CIA: Confidentiality (secrets stay secret — locked diary), Integrity (data is not tampered with — tamper‑proof seal on a medicine bottle), Availability (systems are up when needed — a power generator during a blackout). Encryption scrambles data with a key: symmetric encryption uses the same key to lock and unlock; asymmetric uses a public‑private key pair — think of a public mailbox where anyone can drop a letter but only the owner has the key to open it. Hashing creates a fixed‑size digest, irreversible — a fingerprint of the message.

安全围绕CIA：机密性（Confidentiality）——秘密保持秘密，像上锁的日记本；完整性（Integrity）——数据未被篡改，像药瓶上的防拆封条；可用性（Availability）——需要时系统在线，像停电时的应急发电机。加密用密钥打乱数据：对称加密用同一把钥匙加锁和解锁；非对称加密用公钥/私钥对——想想公共邮箱，任何人都能投信，但只有主人才有开箱的钥匙。哈希产生固定大小的摘要，不可逆——信息的指纹。

12. The CPU Cycle — The Machine’s Heartbeat | CPU周期——机器的心跳

The Fetch‑Decode‑Execute cycle repeats relentlessly. Fetch: the CPU grabs the next instruction from memory, using the Program Counter (PC) as the bookmark. Decode: the Control Unit interprets what the instruction means — a bilingual translator reading machine opcode. Execute: the ALU, registers, and buses perform the actual operation, whether arithmetic or a data move. Then the PC increments, and the heart beats again. Pipelining overlaps these stages for different instructions — an assembly line where one instruction is fetched while the previous one is decoded and the one before that executes.

取指‑译码‑执行循环不停地重复。取指（Fetch）：CPU用程序计数器（PC）作书签，从内存抓取下一条指令。译码（Decode）：控制单元解读指令含义——像阅读机器操作码的双语翻译官。执行（Execute）：ALU、寄存器和总线完成实际操作，可能是算术运算或数据搬运。然后PC递增，心跳再一次跳动。流水线（Pipelining）让不同指令的这些阶段重叠——像一条流水线，取一条指令的同时，前一条在译码，再前面一条在执行。

Published by TutorHao | Pre-U Computer Science Revision Series | aleveler.com

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