📚 Year 10 SQA Computing Science: Core Knowledge Points Review | Year 10 SQA 计算机科学：核心知识点梳理
The Year 10 SQA Computing Science course builds a strong foundation in understanding how computers and software work, from the internal hardware and binary data representation to programming, databases, networks, web technologies, and the legal and ethical implications of digital systems. This revision guide distils the essential knowledge points into twelve focused sections, providing clear explanations with parallel English and Chinese content. Whether you are revising for an assessment or consolidating your learning, each topic is broken down into digestible key facts and concepts to help you master the syllabus efficiently.
Year 10 SQA 计算机科学课程旨在帮助学生打下扎实的基础，理解计算机与软件的运作原理，内容涵盖内部硬件、二进制数据表示、编程、数据库、网络、网页技术以及数字系统的法律与伦理影响。本复习指南将核心知识点浓缩为十二个专题小节，以中英对照的方式清晰解释。无论你是在准备测评还是巩固所学，每个主题都拆解为易于消化的关键事实与概念，助你高效掌握课程要求。
1. Computer Hardware and the CPU | 计算机硬件与中央处理器
A computer system consists of physical components known as hardware. Input devices such as keyboards and sensors feed data into the system; output devices like monitors and speakers convey information to the user. The central processing unit (CPU) is the brain of the computer, responsible for executing instructions. It contains the control unit (CU), which directs the flow of data and decodes instructions, and the arithmetic logic unit (ALU), which performs calculations and logical operations. Registers are high‑speed memory locations inside the CPU that temporarily hold data, addresses, and instructions during processing.
计算机系统由被称为硬件的物理组件构成。键盘、传感器等输入设备将数据送入系统；显示器、扬声器等输出设备则把信息传递给用户。中央处理器（CPU）是计算机的大脑，负责执行指令。它包含控制单元（CU），用于指挥数据流并对指令进行解码；以及算术逻辑单元（ALU），执行计算和逻辑运算。寄存器是CPU内部的高速存储位置，在处理过程中临时保存数据、地址和指令。
The fundamental cycle of the CPU is the fetch‑execute cycle (also called the fetch‑decode‑execute cycle). In the fetch stage, an instruction is brought from main memory (RAM) and placed into the instruction register. The decode stage has the CU interpret the instruction. Finally, in the execute stage, the CPU carries out the instruction, which might involve the ALU performing arithmetic or data being moved between registers. This cycle repeats billions of times per second.
CPU 的基本工作周期是取指‑执行周期（亦称取指‑解码‑执行周期）。在取指阶段，一条指令从主存（RAM）被取出并放入指令寄存器。解码阶段由控制单元对指令进行解释。最后，在执行阶段，CPU 完成该指令，可能由 ALU 执行算术运算，或在寄存器之间移动数据。这一周期每秒钟重复数十亿次。
| CPU Component | Function |
|---|---|
| Control Unit (CU) | Fetches, decodes instructions; controls data flow |
| Arithmetic Logic Unit (ALU) | Performs arithmetic and logical operations |
| Registers | Temporary, fast storage for immediate data and instructions |
Table: Key CPU components and their roles | CPU 关键组件及其作用
2. Data Representation: Binary and Units | 数据表示：二进制与存储单位
Computers use binary (base‑ s follow powers of 2: 1 kilobyte (KB) = approximately 1000 bytes (traditionally 1024 bytes), 1 megabyte (MB) ≈ 10⁶ bytes, 1 gigabyte (GB) ≈ 10⁹ bytes, and 1 terabyte (TB) ≈ 10¹² bytes. Converting binary to denary (base‑ lues where a 1 appears; for example, 1010₂ = (1×2³)+(0×2²)+(1×2¹)+(0×2⁰) = 8+0+2+0 = 10₁₀.
计算机使用二进制（基数为2）表示所有数据，只采用数字0和1。每个二进制位（比特）是最小的数据单位。8个比特构成一个字节。更大的单位遵循2的幂次：1千字节（KB）约等于1000字节（传统为1024字节），1兆字节（MB）≈10⁶字节，1吉字节（GB）≈10⁹字节，1太字节（TB）≈10¹²字节。将二进制转换为十进制（基数为10）需要将出现1的数位值相加；例如 1010₂ = (1×2³)+(0×2²)+(1×2¹)+(0×2⁰) = 8+0+2+0 = 10₁₀。
ers are encoded using standards such as ASCII, where each character is assigned a unique 7‑bit or 8‑bit binary code (e.g., 'A' is 65₁₀ or 0100 0001₂). SQA also introduces hexadecimal (base‑16) as a compact way to represent binary numbers, using digits 0‑9 and letters A‑F (A=10, F=15). For instance, 1010₂ is A₁₆.
文本字符通过ASCII等标准进行编码，每个字符被分配一个唯一的7位或8位二进制代码（例如 'A' 为 65₁₀ 或 0100 0001₂）。SQA 还引入十六进制（基数为16）作为二进制数的紧凑表示法，使用数字0‑9和字母A‑F（A=10，F=15）。例如，1010₂ 即 A₁₆。
3. Memory and Storage | 内存与存储器
Primary memory includes RAM (Random Access Memory) and ROM (Read Only Memory). RAM is volatile, meaning its contents are lost when the power is turned off; it stores the operating system, programs, and data currently in use. ROM is non‑volatile and typically holds the bootstrap loader (the program that starts the computer). Virtual memory allows the computer to use part of the hard drive as an extension of RAM when physical RAM is full, though this is much slower.
主存储器包括随机存取存储器（RAM）和只读存储器（ROM）。RAM 是易失性的，意味着断电后内容会丢失；它存储当前正在使用的操作系统、程序和数据。ROM 是非易失性的，通常保存引导加载程序（启动计算机的程序）。虚拟内存允许在物理 RAM 已满时将硬盘的一部分当作 RAM 的扩展使用，尽管其速度要慢得多。
Secondary storage devices provide non‑volatile, long‑term storage. Common types include magnetic hard disk drives (HDDs), solid‑state drives (SSDs), and optical discs (CDs, DVDs). SSDs have no moving parts, making them faster, quieter, and more durable than HDDs, but typically more expensive per gigabyte. Optical discs use lasers to read and write data and are ideal for distributing media.
辅助存储设备提供非易失性的长期存储。常见的类型包括磁性机械硬盘（HDD）、固态硬盘（SSD）和光盘（CD、DVD）。SSD 没有移动部件，因此比 HDD 更快、更安静、更耐用，但每吉字节的成本通常更高。光盘利用激光读写数据，非常适合分发媒体内容。
4. System Software and Operating Systems | 系统软件与操作系统
System software manages the hardware and provides a platform for application software. The operating system (OS) is the core system software. It performs several vital functions: memory management (allocating RAM to programs), multitasking (allowing multiple applications to run seemingly simultaneously), file management (organising data on storage), providing a user interface (GUI or command line), and managing input/output operations such as printing.
系统软件负责管理硬件，并为应用软件提供运行平台。操作系统（OS）是核心的系统软件。它执行若干重要功能：内存管理（为程序分配 RAM）、多任务处理（允许多个应用程序看似同时运行）、文件管理（组织存储设备上的数据）、提供用户界面（图形界面或命令行）以及管理输入/输出操作（如打印）。
Utility software helps maintain, analyse, and protect the computer. Examples include antivirus software (detecting and removing malware), disk defragmentation tools (reorganising files to improve access speed), backup utilities (copying data to prevent loss), and disk cleaners (removing temporary files). Without these utilities, system performance and security can degrade over time.
实用工具软件有助于维护、分析和保护计算机。例如：杀毒软件（检测并清除恶意软件）、磁盘碎片整理工具（重新组织文件以提高访问速度）、备份工具（复制数据以防丢失）以及磁盘清理工具（删除临时文件）。没有这些工具，系统的性能与安全性会随时间推移而下降。
5. Programming Fundamentals: Variables and Data Types | 编程基础：变量与数据类型
In programming, a variable is a named storage location whose value can change while the program runs. Constants are named values that cannot be modified after initialisation. Variables must be declared with a data type. Common data types include integer (whole numbers), real/float (numbers with decimal points), Boolean (TRUE/FALSE), string (sequence of characters), and character (a single letter, digit, or symbol).
在编程中，变量是具有名称的存储位置，其值可在程序运行时改变。常量是初始化后不可修改的命名值。变量必须以某种数据类型声明。常见的数据类型有：整型（整数）、实型/浮点型（带小数点的数字）、布尔型（TRUE/FALSE）、字符串（字符序列）以及字符型（单个字母、数字或符号）。
An array is a data structure that can store multiple values of the same type under a single identifier. One‑dimensional (1D) arrays are like lists; elements are accessed using an index, typically starting at 0. For example, in pseudocode: DECLARE scores AS ARRAY OF INTEGER INITIALLY [12, 9, 15]. The value scores[1] would be 9.
数组是一种数据结构，可用一个标识符存储多个同一类型的值。一维（1D）数组类似于列表；通过索引访问元素，索引通常从0开始。例如，用伪代码表示为：DECLARE scores AS ARRAY OF INTEGER INITIALLY [12, 9, 15]。scores[1] 的值是 9。
6. Programming Constructs: Sequence, Selection, Iteration | 编程结构：顺序、选择与迭代
Every program is built using three basic control structures. Sequence means statements are executed in the order they appear, one after another. Selection allows the program to make decisions. The IF…THEN…ELSE statement chooses between alternative paths based on a condition. A CASE (or switch) statement selects one of several blocks depending on the value of a variable.
每个程序都由三种基本控制结构构建而成。顺序意味着语句按照出现的先后次序依次执行。选择允许程序作出决定。IF…THEN…ELSE 语句根据条件在两条路径中选择其一。CASE（或 switch）语句则根据变量的值从多个代码块中选择一个执行。
Iteration (looping) repeats a block of code. A fixed loop (FOR loop) repeats a set number of times, for example: FOR counter FROM 1 TO 5 DO … END FOR. Conditional loops repeat as long as (or until) a condition is met: the WHILE loop checks the condition at the start; the REPEAT…UNTIL loop checks at the end, guaranteeing at least one execution. Choosing the correct loop helps manage program logic efficiently.
迭代（循环）重复执行一段代码。固定循环（FOR 循环）按设定次数重复，例如：FOR counter FROM 1 TO 5 DO … END FOR。条件循环在满足某个条件时一直重复（或直到条件满足）：WHILE 循环在开头检查条件；REPEAT…UNTIL 循环在末尾检查，保证至少执行一次。选择合适的循环有助于高效管理程序逻辑。
7. Subprograms and Modularity | 子程序与模块化
Subprograms are self‑contained blocks of code that perform a specific task. In SQA terminology, a procedure carries out a task without returning a value, while a function returns a value. Parameters (or arguments) allow data to be passed into subprograms, making them flexible. For instance, FUNCTION calculateArea(length, width) RETURNS REAL would take measurements and return the area.
子程序是完成特定任务的自包含代码块。按照 SQA 的术语，过程（procedure）执行一个任务但不返回值，而函数（function）则返回一个值。参数（或实参）允许将数据传递给子程序，使其更加灵活。例如，FUNCTION calculateArea(length, width) RETURNS REAL 会接收测量值并返回面积。
Modular programming involves dividing a large program into smaller, manageable subprograms. This brings several benefits: reusability (the same module can be used in multiple programs), easier debugging and testing (modules can be checked independently), and the ability for teams to work on different parts simultaneously. Well‑designed modules reduce complexity and improve code readability.
模块化编程涉及将大型程序划分成更小、易于管理的子程序。这带来若干好处：可重用性（同一模块可用于多个程序）、更易于调试和测试（可独立检查各模块）以及团队能够同时开发不同部分。设计良好的模块可降低复杂性并提高代码可读性。
8. Testing and Debugging | 测试与调试
Testing ensures a program works correctly under all expected conditions. Three categories of test data are used: normal data (typical, acceptable inputs that should produce correct outputs), extreme data (values at the boundaries of acceptable ranges, e.g., minimum and maximum), and exceptional data (invalid inputs that should be rejected gracefully). Comprehensive testing employs all three.
测试能确保程序在所有预期条件下正确运行。使用三类测试数据：正常数据（典型的、可接受的输入，应产生正确输出）、极端数据（位于可接受范围边界的值，如最小值和最大值），以及异常数据（无效输入，应被妥善拒绝）。全面的测试应兼顾三者。
Debugging is the process of finding and fixing errors (bugs) in code. Common techniques include dry‑running (stepping through code manually with pencil and paper), using trace tables to record variable values at each step, and employing breakpoints or print statements to inspect the program state. A trace table helps identify logical errors where the program behaves unexpectedly.
调试是指查找并修正代码中错误（bug）的过程。常用技术包括：手工走查（用纸笔逐步执行代码）、使用跟踪表记录每一步的变量值，以及借助断点或打印语句来检查程序状态。跟踪表有助于发现导致程序行为异常的逻辑错误。
9. Databases and SQL | 数据库与 SQL
A relational database stores data in tables, which are made up of records (rows) and fields (columns). Each table usually has a primary key—a field that uniquely identifies each record, such as a StudentID. Foreign keys link tables together, establishing relationships. Common field data types include INTEGER, REAL, VARCHAR (text), DATE, and BOOLEAN.
关系型数据库将数据存储在表中，表由记录（行）和字段（列）构成。每个表通常有一个主键——能够唯一标识每条记录的字段，例如 StudentID。外键则将表关联起来，建立关系。常见的字段数据类型包括 INTEGER、REAL、VARCHAR（文本）、DATE 和 BOOLEAN。
SQL (Structured Query Language) is used to interact with databases. The most common query retrieves data: SELECT field1, field2 FROM Table WHERE condition ORDER BY field ASC;. To insert a new record: INSERT INTO Table (field1, field2) VALUES (value1, value2);. Updating uses UPDATE Table SET field1 = value WHERE condition;, and deletion uses DELETE FROM Table WHERE condition;. Understanding these basic statements enables data manipulation in practical tasks.
结构化查询语言（SQL）用于与数据库交互。最常见的查询操作为检索数据：SELECT field1, field2 FROM Table WHERE condition ORDER BY field ASC;。插入新记录：INSERT INTO Table (field1, field2) VALUES (value1, value2);。更新使用 UPDATE Table SET field1 = value WHERE condition;，删除使用 DELETE FROM Table WHERE condition;。理解这些基本语句便可在实际操作中操纵数据。
10. Computer Networks and Communication | 计算机网络与通信
Networks connect computers to share resources and data. A Local Area Network (LAN) covers a small geographical area, such as a school or office, using cables or Wi‑Fi. A Wide Area Network (WAN) connects LANs over larger distances, often using telephone lines, fibre optics, or satellite links; the internet is the largest WAN.
网络将计算机连接起来以共享资源和数据。局域网（LAN）覆盖较小的地理区域，如学校或办公室，使用电缆或 Wi‑Fi。广域网（WAN）在更大范围内连接多个局域网，通常借助电话线、光纤或卫星链路；互联网是最大的广域网。
Network topology describes how devices are physically or logically arranged. In a star topology, each device connects to a central switch; if one link fails, only that device is affected. A bus topology uses a single backbone cable; it is simpler but a cable break can halt the entire network. Common hardware includes switches (connect devices within a LAN), routers (connect different networks and direct traffic), and network interface cards (NICs) that provide a connection point.
网络拓扑描述了设备的物理或逻辑排列方式。在星形拓扑中，每台设备连接到一台中央交换机；如果一条链路故障，只有该设备受影响。总线形拓扑使用一条主干电缆；它较简单，但一处电缆断裂可能导致整个网络瘫痪。常见的网络硬件包括交换机（连接局域网内的设备）、路由器（连接不同网络并引导流量）以及提供接入点的网卡（NIC）。
Protocols are sets of rules that govern communication. TCP/IP is the fundamental protocol suite for the internet, ensuring data is split into packets, routed, and reassembled correctly. HTTP/HTTPS is for web pages, FTP for file transfers, and SMTP for sending emails. Network security features such as firewalls, encryption (e.g., WPA2 for Wi‑Fi), and strong passwords help protect data from unauthorised access.
协议是管理通信的规则集合。TCP/IP 是互联网的基本协议簇，确保数据被分解为数据包、正确路由并重新组装。HTTP/HTTPS 用于网页传输，FTP 用于文件传输，SMTP 用于发送电子邮件。防火墙、加密（例如 Wi‑Fi 的 WPA2）和强密码等网络安全措施有助于保护数据免受未授权访问。
11. Web Technologies: HTML, CSS, JavaScript | 网页技术：HTML、CSS、JavaScript
HTML (Hypertext Markup Language) defines the structure and content of a webpage using elements enclosed in tags. Common tags include <h1> to <h6> for headings, <p> for paragraphs, <img> for images, and <a> for hyperlinks. An HTML document begins with a <!DOCTYPE html> declaration and contains <head> and <body> sections.
HTML（超文本标记语言）使用标签中的元素定义网页的结构与内容。常见标签包括：<h1> 至 <h6> 表示标题，<p> 表示段落，<img> 表示图像，<a> 表示超链接。HTML 文档以 <!DOCTYPE html> 声明开始，并包含 <head> 和 <body> 部分。
CSS (Cascading Style Sheets) controls the presentation and layout of HTML elements, such as colours, fonts, spacing, and positioning. Styles can be applied inline, internally within a <style> tag, or externally through a separate .css file linked using <link rel="stylesheet">. Selectors target elements (e.g., p, .class, #id) to apply specific rules.
CSS（层叠样式表）控制 HTML 元素的呈现与布局，如颜色、字体、间距和定位。样式可通过内联方式、在 <style> 标签内部，或通过 <link rel="stylesheet"> 链接独立 .css 文件的外部方式应用。选择器（如 p、.class、#id）用于定位元素并应用特定规则。
JavaScript adds interactivity and dynamic behaviour to web pages. It can respond to events (e.g., button clicks), validate form inputs before submission, and modify HTML/CSS on the fly. For example, a simple script might check that an email field contains the '@' symbol. JavaScript is placed inside <script> tags and can be linked externally.
JavaScript 为网页增添交互性与动态行为。它可以响应事件（例如按钮点击）、在提交前验证表单输入，并即时修改 HTML/CSS。例如，一个简单脚本可检查电子邮件字段是否包含 '@' 符号。JavaScript 放在 <script> 标签内，也可外链引用。
12. Legal, Ethical and Environmental Impacts | 法律、道德与环境影响
The use of computers is governed by legislation. In the UK, the Computer Misuse Act (1990) makes it illegal to access computer material without permission (hacking), to commit further offences once inside, and to impair the operation of computers (e.g., spreading viruses). The Data Protection Act (2018), which incorporates GDPR, requires organisations to handle personal data lawfully, transparently, and securely, giving individuals rights over their data.
计算机的使用受到法律约束。在英国，《计算机滥用法》（1990年）规定，未经许可访问计算机资料（黑客行为）、进入系统后实施进一步犯罪以及妨碍计算机运行（如传播病毒）均属违法。《数据保护法》（2018年）纳入了《通用数据保护条例》，要求组织合法、透明、安全地处理个人数据，赋予个人对自己数据的权利。
Copyright law (e.g., Copyright, Designs and Patents Act) protects original creative works, including software, music, and images. Illegal peer‑to‑peer file sharing and software piracy are offences. Ethical considerations extend to the responsible use of IT: respecting privacy, avoiding cyberbullying, and understanding professional conduct. Ethical hacking (white hat) involves authorised testing to improve security, unlike malicious cracking.
版权法（如《版权、外观设计和专利法》）保护包括软件、音乐和图像在内的原创作品。非法的点对点文件共享和软件盗
Published by TutorHao | Year 10 Computer Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图