📚 Year 7 Cambridge Computing: Core Knowledge Overview | Year 7 Cambridge 计算机：核心知识点梳理
This article summarises the essential topics covered in the Year 7 Cambridge Computing curriculum. You will explore computer hardware, software, binary data, networks, online safety, algorithms, Scratch programming, and computational thinking – all explained step by step to build a solid foundation.
本文梳理了 Year 7 Cambridge 计算机课程的核心知识点。你将学习计算机硬件、软件、二进制数据、网络、网络安全、算法、Scratch 编程以及计算思维，通过逐步讲解帮助你打下扎实的基础。
1. Computer Systems and Hardware | 计算机系统与硬件
A computer system is made up of hardware (the physical parts you can touch) and software (the instructions that tell the hardware what to do). Together they process data and help us complete tasks such as writing, browsing the internet, or playing games.
计算机系统由硬件（你可以触摸到的物理部件）和软件（告诉硬件要做什么的指令）组成。它们协同工作处理数据，帮助我们完成写作文、上网或玩游戏等任务。
The Central Processing Unit (CPU) is often called the 'brain' of the computer. It carries out instructions using a fetch-decode-execute cycle, performing calculations and making decisions.
中央处理器（CPU）常被称为计算机的「大脑」。它通过取指-译码-执行周期来执行指令，完成运算与逻辑判断。
Memory comes in two main types: RAM (Random Access Memory) holds data and programs currently in use, but it is volatile – it loses everything when power is turned off. ROM (Read Only Memory) stores permanent instructions like the startup process and is non-volatile.
存储器主要分为两种：RAM（随机存取存储器）保存正在使用的数据和程序，但是易失性的——断电后内容会丢失。ROM（只读存储器）储存启动程序等永久指令，是非易失性的。
Storage devices keep data safe for the long term. Hard Disk Drives (HDD) use spinning magnetic disks, while Solid State Drives (SSD) use flash memory and are much faster. USB sticks and memory cards are portable storage.
存储设备长期保存数据。硬盘驱动器（HDD）使用旋转的磁性盘片，而固态硬盘（SSD）使用闪存，速度更快。U盘和存储卡是便携式存储设备。
Input devices let us send information into the computer – keyboards, mice, touchscreens, microphones and scanners. Output devices display or communicate results – monitors, printers, speakers and headphones.
输入设备让我们把信息送入计算机——键盘、鼠标、触摸屏、麦克风和扫描仪。输出设备显示或传送结果——显示器、打印机、音箱与耳机。
2. Software: System and Application Software | 软件：系统软件与应用软件
Software can be divided into two categories. System software manages the hardware and provides a platform for other software to run. The operating system (e.g., Windows, macOS, Linux) is the most important system software.
软件可分为两大类。系统软件管理硬件并为其他软件提供运行平台。操作系统（如 Windows、macOS、Linux）就是最重要的系统软件。
Application software helps users perform specific tasks. Examples include word processors for writing documents, spreadsheets for calculations, web browsers for surfing the internet, and games for entertainment.
应用软件帮助用户完成特定任务。例如文字处理软件用于写文档、电子表格用于计算、网页浏览器用于上网、游戏用于娱乐。
Utility software is a special type of system software that maintains and protects the computer. Antivirus programs, disk cleaners, and backup tools are all utilities – they keep the system healthy and secure.
实用工具软件是一类特殊的系统软件，负责维护和保护计算机。杀毒程序、磁盘清理工具和备份工具都是实用工具——它们保持系统健康与安全。
3. Binary and Data Representation | 二进制与数据表示
Computers use the binary number system, which has only two digits: 0 and 1. Each binary digit is called a 'bit'. A group of 8 bits makes one byte, capable of representing 256 different values (from 0 to 255).
计算机使用二进制数制，它只有两个数码：0 和 1。每一个二进制位称为一个「比特」。8 个比特组成一个字节，可以表示 256 种不同的值（从 0 到 255）。
rom right to left are 2⁰ = 1, 2¹ = 2, 2² = 4, 2³ = 8, 2⁴ = 16, 2⁵ = 32, 2⁶ = 64, 2⁷ = 128.
将二进制转换为十进制时，用每一位乘以位权（2 的幂）再求和。从右向左的位权依次是 2⁰ = 1, 2¹ = 2, 2² = 4, 2³ = 8, 2⁴ = 16, 2⁵ = 32, 2⁶ = 64, 2⁷ = 128。
Example: Binary 01000001 = (0×128)+(1×64)+(0×32)+(0×16)+(0×8)+(0×4)+(0×2)+(1×1) = 65
Text characters are represented using codes. ASCII (American Standard Code for Information Interchange) assigns a 7-bit binary number to each letter, digit, and symbol. For instance, the capital letter 'A' has the binary code 1000001 (decimal 65).
文字字符用编码表示。ASCII（美国信息交换标准代码）为每个字母、数字和符号分配一个 7 位二进制数。例如大写字母 'A' 的二进制码是 1000001（十进制 65）。
4. Fundamentals of Computer Networks | 计算机网络基础
A network connects two or more computers so they can share data, resources (like printers), and internet access. The smallest network is a Personal Area Network (PAN) linking devices close to a single person, often using Bluetooth.
网络将两台或多台计算机连接起来，使它们可以共享数据、资源（如打印机）和互联网接入。最小的网络是个域网（PAN），连接个人身边很近的设备，通常使用蓝牙。
A Local Area Network (LAN) covers a small geographical area, such as a school or an office building. Devices in a LAN are connected using Ethernet cables or Wi‑Fi. A Wide Area Network (WAN) connects LANs over large distances – the internet is the largest WAN.
局域网（LAN）覆盖较小的地理范围，如一所学校或一栋办公楼。局域网中的设备通过以太网线或 Wi‑Fi 连接。广域网（WAN）则跨越大范围连接局域网——互联网就是最大的广域网。
Networks need hardware like switches (which connect devices within a LAN) and routers (which connect different networks and direct data traffic). A modem converts digital signals into a form that can travel over telephone or cable lines.
网络需要交换机（在局域网内连接设备）和路由器（连接不同网络并引导数据流量）等硬件。调制解调器将数字信号转换成可以在电话线或有线电视线上传输的形式。
Network speeds are measured in bits per second (bps). Common units are Mbps (megabits per second) and Gbps (gigabits per second). A higher bandwidth means more data can be sent at the same time.
网络速度以比特每秒（bps）来度量。常见的单位有 Mbps（兆比特每秒）和 Gbps（千兆比特每秒）。带宽越高，同一时间能传输的数据就越多。
5. The Internet and the World Wide Web | 互联网与万维网
The Internet is a global network of interconnected computers that communicate using protocols such as TCP/IP. The World Wide Web (WWW) is a service that runs on the internet, consisting of web pages accessed through browsers.
互联网是由相互连接的计算机组成的全球性网络，使用 TCP/IP 等协议通信。万维网（WWW）是运行在互联网上的一项服务，由通过浏览器访问的网页组成。
A Uniform Resource Locator (URL) is the address of a web page. It typically contains the protocol (https://), the domain name (e.g., www.example.com), and the path to a specific page or file.
统一资源定位符（URL）是网页的地址。它通常包含协议（https://）、域名（例如 www.example.com）以及指向特定页面或文件的路径。
Web browsers (Chrome, Safari, Edge) interpret HTML, CSS, and JavaScript to display formatted web pages. Search engines like Google use automated 'crawlers' to index billions of pages and help users find information quickly.
网页浏览器（Chrome、Safari、Edge）解析 HTML、CSS 和 Javascript，将格式化后的网页显示出来。像 Google 这样的搜索引擎使用自动化的「爬虫」为数十亿页面编制索引，帮助用户快速找到信息。
When you type a web address, your device sends a request through a series of routers, often passing through an Internet Service Provider (ISP). The server hosting the page sends back the data, which your browser renders.
当你输入网址时，设备通过一连串路由器发出请求，通常经过互联网服务提供商（ISP）。存放该页面的服务器将数据发回，浏览器再将其呈现出来。
6. Online Safety and Digital Citizenship | 网络安全与数字公民
Creating strong passwords is the first line of defence. A strong password uses a mix of uppercase and lowercase letters, numbers, and symbols, and should be at least eight characters long. Avoid using personal information like your name or birthday.
创建强密码是第一道防线。强密码混合大小写字母、数字和符号，长度至少八位。避免使用姓名或生日等个人信息。
Never share personal details (full name, address, phone number, school name) with strangers online. What you post can stay on the internet forever, even if you delete it – this is called your digital footprint.
永远不要向网上的陌生人透露个人信息（全名、地址、电话号码、学校名称）。你发布的内容即使在删除后也可能永久留在互联网上——这称为数字足迹。
Cyberbullying is using technology to harass, threaten, or embarrass someone. If you experience or witness cyberbullying, tell a trusted adult and use the report and block features built into most apps and websites.
网络欺凌是指利用技术手段骚扰、威胁或使人难堪。如果你遭遇或目睹网络欺凌，要告诉信任的成年人，并使用多数应用程序和网站内置的举报与拉黑功能。
Respecting intellectual property means you should not download or share copyrighted music, films, or software without permission. Always check the terms of use and give credit when using someone else's work.
尊重知识产权意味着未经许可不得下载或分享受版权保护的音乐、电影或软件。使用他人作品时务必查看使用条款并注明出处。
7. Algorithms and Flowcharts | 算法与流程图
An algorithm is a step-by-step set of instructions to solve a problem or complete a task. You use algorithms in daily life, such as following a recipe, tying shoelaces, or giving directions to a friend.
算法是解决问题或完成任务的一系列步骤。你每天都在使用算法，例如按照食谱做菜、系鞋带或给朋友指路。
Algorithms must be clear, ordered, and finite – they have a definite start and end. When designing an algorithm, you can think in three building blocks: sequence (steps in order), selection (making a choice with 'if'), and iteration (repeating steps).
算法必须清晰、有序且有限——有明确的开始和结束。设计算法时，你可以用三个基本构件来思考：顺序（按序执行）、选择（用「如果」做决定）和迭代（重复步骤）。
Flowcharts are diagrams that represent algorithms using standard symbols. An oval shows Start or End, a rectangle shows a process or instruction, a diamond shows a decision (with Yes/No branches), and arrows show the flow direction.
流程图是使用标准符号表示算法的图示。椭圆形表示开始或结束，矩形表示过程或指令，菱形表示判断（带有是/否分支），箭头表示流程的方向。
Pseudocode is another way to plan algorithms – n English that looks a little like programming code but without strict rules. For example: 'INPUT age, IF age ≥ 13 THEN OUTPUT "teenager"'.
伪代码是规划算法的另一方式——它使用类似编程代码的简明英语，但没有严格的语法规则。例如：「输入年龄，如果年龄 ≥ 13 则输出“青少年”」。
8. Introduction to Programming with Scratch | Scratch 编程入门
Scratch is a block-based visual programming language where you drag and snap together code blocks to create interactive stories, games, and animations. The main area is called the Stage, where your creations come to life.
Scratch 是一种基于积木的可视化编程语言，你可以拖拽并拼合代码积木来创作互动故事、游戏和动画。主区域称为舞台，你的作品就在那里呈现。
Characters and objects in Scratch are called sprites. Each sprite can have its own scripts (code), costumes (appearance frames), and sounds. You control sprites using blocks from different categories: Motion, Looks, Sound, Events, Control, Sensing, Operators, and Variables.
Scratch 中的角色和物体称为精灵。每个精灵都可以拥有自己的脚本（代码）、造型（外观帧）和声音。你使用来自不同类别的积木来控制精灵：运动、外观、声音、事件、控制、侦测、运算和变量。
An event block (e.g., 'when green flag clicked') starts a script. Loops (repeat blocks) let you run the same code multiple times – a 'forever' block runs repeatedly until the program stops. Conditional blocks ('if … then') make decisions based on conditions.
事件积木（如「当绿旗被点击」）启动脚本。循环积木（重复执行）让你多次运行同一段代码——「重复执行」积木会不断运行直到程序停止。条件积木（「如果……那么」）根据条件做出判断。
Broadcast messages allow sprites to communicate. One sprite can broadcast a message, and other sprites can react when they receive that message. This is useful for coordinating actions like starting a game level.
广播消息让精灵之间能相互通信。一个精灵可以广播一条消息，其他精灵接收到该消息时可以做出反应。这对于协调开始游戏关卡等操作非常有用。
9. Variables and Input/Output | 变量与输入/输出
A variable is a named container that stores a piece of data, such as a score, a player's name, or the number of lives left. In Scratch, you can create a variable and use blocks to set it, change it, or display it on the stage.
变量就是一个有名字的容器，用来存放一块数据，比如分数、玩家姓名或剩余生命数。在 Scratch 中，你可以创建变量，并使用积木来设定、改变或在舞台上显示它。
Input means getting data from the user. The 'ask … and wait' block in Scratch opens a text box, and the user's answer is stored in the built-in variable 'answer'. This is an example of interactive programming.
输入是指从用户获取数据。Scratch 中的「询问……并等待」积木会打开一个文本框，用户的回答会被存储在名为「回答」的内置变量里。这是交互式编程的一个例子。
Output is how the program communicates back to the user. It can be visual (the sprite says something, changes costume, or moves) or audio (playing a sound). The 'say … for 2 seconds' block is a simple output block.
输出是程序向用户反馈的方式。它可以是视觉的（精灵说话、改换造型或移动）或听觉的（播放声音）。「说……2 秒」积木就是一种简单的输出积木。
Using variables together with loops allows you to keep a running total. For instance, you can set a score to 0, then repeatedly increase it by 1 each time a condition is met, and display the current score.
将变量与循环结合使用可以保持累计总和。例如，你可以先将分数设为 0，每当满足条件时就重复加 1，然后显示当前分数。
10. Problem Solving and Computational Thinking | 问题解决与计算思维
Computational thinking is a way of solving problems that draws on concepts from computer science. It consists of four key techniques: decomposition, pattern recognition, abstraction, and algorithm design.
计算思维是一种借鉴计算机科学概念的问题解决方法。它包含四项核心技术：分解、模式识别、抽象和算法设计。
Decomposition means breaking a large, complex problem into smaller, more manageable parts. For example, planning a school trip can be divided into transport, food, budget, and activities – each part solved separately.
分解是指将一个庞大复杂的问题拆分成更小、更易于管理的部分。例如，策划校外旅行可以分解为交通、食物、预算和活动——每个部分单独解决。
Pattern recognition involves looking for similarities or trends within problems. If you notice that a repeating sequence of shapes in a game predicts when a bonus appears, you can use that pattern to score higher.
模式识别指在问题中寻找相似性或规律。如果你发现游戏中重复的形状序列能预测奖励何时出现，就可以利用这个模式获得更高分数。
Abstraction focuses on the important details while filtering out unnecessary information. When drawing a map of a neighbourhood, you might include roads and landmarks but leave out individual trees or parked cars.
抽象是关注重要细节，同时过滤掉不必要的信息。在绘制社区地图时，你可能会标出道路和地标，而省略掉单棵树或停着的汽车。
Finally, algorithm design puts together a clear, step-by-step plan to solve the original problem. The step-by-step solution can then be tested and improved, which is an essential skill for every young programmer.
最后，算法设计是将清晰的、一步步的计划组合起来解决原始问题。这一步步的方案可以不断测试与改进，这是每个年轻程序员都必须掌握的重要技能。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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