📚 Year 7 WJEC Computer Science Core Knowledge Checklist | WJEC 七年级计算机：核心知识点梳理
Welcome to your Year 7 Computer Science journey! This article brings together every essential idea you will meet in the WJEC curriculum – from how a computer works inside to the first steps of coding and staying safe online. Read each section carefully, compare the English and Chinese explanations, and use the checklists to track your own understanding.
欢迎开启七年级计算机科学的学习之旅！本文汇总了 WJEC 课程中的每一个核心概念——从计算机的内部工作原理到编程入门，再到如何安全上网。请仔细阅读每一节，对照中英文解释，并用清单检查自己的掌握情况。
1. What is a Computer? | 什么是计算机？
can be a desktop PC, a laptop, a tablet, a smartphone, or even a tiny chip inside a microwave. All computers share the same basic model: input → process → output.
计算机是一种电子设备，它接收数据（输入），按照一组指令进行处理，然后产生结果（输出）。它可以是台式机、笔记本、平板、智能手机，甚至是微波炉里的一小块芯片。所有计算机都遵循同一个基本模型：输入 → 处理 → 输出。
- Input devices send information into the computer (keyboard, mouse, touchscreen).
- 输入设备把信息送入计算机（键盘、鼠标、触摸屏）。
- The central processing unit (CPU) carries out the processing.
- 中央处理器（CPU）负责处理工作。
- Output devices show or play the result (monitor, printer, speakers).
- 输出设备展示或播放结果（显示器、打印机、音箱）。
2. Hardware and Software | 硬件与软件
Hardware is any physical part of a computer you can touch – the case, the motherboard, the screen, the cables. Software is the collection of programs and instructions that tell the hardware what to do. Without software, hardware is just a box of electronics; without hardware, software has nowhere to run.
硬件是计算机中你能触摸到的物理部件——机箱、主板、屏幕、线缆。软件是指告诉硬件做什么的程序和指令的集合。没有软件，硬件只是一堆电子元件；没有硬件，软件无处运行。
- Examples of hardware: monitor, keyboard, RAM chips, hard disk.
- 硬件例子：显示器、键盘、内存条、硬盘。
- Examples of software: operating system (Windows, macOS), apps (web browser, games), utility programs (antivirus).
- 软件例子：操作系统（Windows、macOS），应用程序（网页浏览器、游戏），工具软件（杀毒软件）。
3. Input, Output and Storage Devices | 输入、输出与存储设备
Devices around a computer can be grouped by what they do. Input devices let you put data in – keyboard, mouse, microphone, scanner. Output devices let the computer give information back to you – monitor, printer, headphones. Storage devices keep data safe for later use – hard drive, USB stick, memory card.
计算机周围的设备可以按功能分组。输入设备让你把数据放进去——键盘、鼠标、麦克风、扫描仪。输出设备让计算机把信息传回给你——显示器、打印机、耳机。存储设备把数据保存起来供以后使用——硬盘、U盘、存储卡。
- Storage can be internal (inside the computer) or external (plugged in).
- 存储设备可以是内置的（在电脑内部）或外置的（插入连接）。
- Capacity is measured in bytes: kilobyte (KB), megabyte (MB), gigabyte (GB), terabyte (TB).
- 容量用字节衡量：千字节 (KB)、兆字节 (MB)、吉字节 (GB)、太字节 (TB)。
4. The Central Processing Unit (CPU) | 中央处理器 (CPU)
The CPU is the "brain" of the computer. It follows a cycle called fetch–decode–execute: it fetches an instruction from memory, decodes (works out what it means), and then executes (carries it out). Modern CPUs can do billions of these cycles every second. The speed is measured in gigahertz (GHz).
CPU 是计算机的“大脑”。它遵循一个叫作取指–译码–执行的循环：从内存中取出一条指令，译码（弄清它的含义），然后执行（把它完成）。现代 CPU 每秒能进行数十亿次这样的循环。速度以吉赫兹（GHz）为单位。
- More cores in a CPU mean it can work on several tasks at the same time.
- CPU 的内核越多，就能同时处理多件任务。
- A faster clock speed usually means better performance, but heat and power use also increase.
- 时钟速度越快通常性能越好，但发热和功耗也会增加。
5. Memory: RAM and ROM | 内存：RAM 与 ROM
Primary memory is directly connected to the CPU. RAM (Random Access Memory) is volatile – it loses its content when the power is turned off. It holds the programs and data currently in use. ROM (Read Only Memory) is non-volatile – it keeps its content even without power and usually stores the instructions needed to start the computer (BIOS or firmware).
主存储器直接与 CPU 相连。RAM（随机存取存储器）是易失性的——断电后内容会丢失。它存放当前正在使用的程序和数据。ROM（只读存储器）是非易失性的——即使没有电源也能保留内容，通常保存开机所需的指令（BIOS 或固件）。
- Think of RAM as your desk space: the bigger the desk, the more books you can have open at once.
- 把 RAM 想象成你的桌面：桌面越大，你就能同时摊开更多的书。
- ROM is like the school handbook that never changes – always available when you turn up.
- ROM 则像学校里永不更改的学生手册——你一上学就能用到。
6. Binary and Data Representation | 二进制与数据表示
Computers use binary because their circuits have two states: on (1) and off (0). All data – numbers, text, pictures, sound – is stored as patterns of 1s and 0s. A single 0 or 1 is called a bit. Eight bits make one byte. Characters are often encoded using ASCII or Unicode, where each letter or symbol gets a unique binary number.
计算机使用二进制，因为它的电路只有两种状态：开 (1) 和关 (0)。所有数据——数字、文字、图片、声音——都以 1 和 0 的模式存储。一个单独的 0 或 1 叫作一位 (bit)。八位组成一个字节 (byte)。字符通常用 ASCII 或 Unicode 编码，每个字母或符号都有一个唯一的二进制编号。
- Example: the letter 'A' is 01000001 in ASCII.
- 例如：字母 'A' 的 ASCII 编码是 01000001。
- Images are made of tiny dots called pixels, each with a binary code for colour.
- 图像由叫作像素的小点组成，每个像素都有一个表示颜色的二进制编码。
7. Networks and the Internet | 网络与互联网
A network is two or more computers linked together so they can share files, printers, or an internet connection. A LAN (Local Area Network) covers a small area like a school or home. The internet is a huge global network connecting millions of smaller networks. Data travels in small packets, following rules called protocols (e.g. TCP/IP).
网络是将两台或多台计算机连接起来，以便共享文件、打印机或互联网连接。LAN（局域网）覆盖学校或家庭等小范围区域。互联网是一个巨大的全球网络，连接着数以百万计的较小网络。数据以少量分组（数据包）的形式传输，遵循称为协议的规则（如 TCP/IP）。
- Wi‑Fi uses radio waves to connect devices without cables.
- Wi‑Fi 利用无线电波连接设备，无需线缆。
- A router directs traffic between your home network and the internet.
- 路由器在你的家庭网络和互联网之间引导通信。
8. Staying Safe Online | 安全上网
Whenever you go online, you leave a digital footprint. Keep personal information private – never share your full name, address, school, or passwords with strangers. Use strong passwords (a mix of letters, numbers and symbols). Be kind and respectful in messages, and tell a trusted adult if something makes you uncomfortable.
每次上网，你都会留下数字足迹。请保护个人信息——永远不要把全名、地址、学校或密码告诉陌生人。使用强密码（字母、数字和符号的组合）。在消息中保持友善和尊重，如果有什么让你感到不舒服，一定要告诉信任的成年人。
- Phishing is when fake emails or messages try to trick you into giving away private information.
- 网络钓鱼是指虚假邮件或信息试图诱骗你泄露私人信息。
- Cyberbullying is repeated, harmful behaviour online – it is never acceptable.
- 网络欺凌是指网络上反复出现的伤害行为——这绝不可接受。
9. Computational Thinking | 计算思维
Computational thinking is a way of solving problems like a computer scientist. It has three main techniques: decomposition (breaking a big problem into smaller parts), pattern recognition (spotting similarities), and abstraction (focusing on important details and ignoring irrelevant ones). These skills help you plan a solution before you write any code.
计算思维是一种像计算机科学家那样解决问题的方法。它包含三种主要技巧：分解（把大问题拆成小部分），模式识别（发现相似之处），抽象化（关注重要细节，忽略无关信息）。这些技能能帮你在编写代码之前策划好解决方案。
- Example: Organising a school talent show can be decomposed into tasks such as room booking, performer list, and publicity.
- 例如：组织学校才艺秀可以分解为预约场地、表演者名单、宣传活动等子任务。
- Pattern recognition sees that many tasks repeat every year, so you can reuse last year’s plan.
- 模式识别发现许多任务每年都重复，因此你可以沿用去年的计划。
10. 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. It must be precise and in the right order. Flowcharts use symbols to represent an algorithm visually: ovals for start/end, rectangles for processes, diamonds for decisions, and arrows for the flow.
算法是解决问题或完成任务的一步一步的指令集。它必须精确且顺序正确。流程图用符号来直观地表示算法：椭圆表示开始/结束，矩形表示处理步骤，菱形表示判断，箭头表示流程方向。
- Example algorithm: making a cup of tea – fill kettle with water, boil, put tea bag in cup, pour water, wait, remove tea bag, add milk.
- 算法示例：泡一杯茶——给水壶加水，煮沸，把茶包放入杯中，倒水，等待，取出茶包，加牛奶。
- Decision symbol means a question that can be answered yes or no, leading to two different paths.
- 判断符号表示一个可回答是或否的问题，导致两条不同的路径。
11. Programming Basics: Sequence, Selection, Iteration | 编程基础：顺序、选择、循环
Every program is built from three simple structures. Sequence means doing steps one after another in order. Selection means making a choice – if a condition is true do one thing, otherwise do something else (IF–THEN–ELSE). Iteration means repeating a set of instructions (a loop). Loops can be count‑controlled (repeat 10 times) or condition‑controlled (repeat until something happens).
每一个程序都由三种简单结构构成。顺序是指按先后次序一步一步执行。选择是指做出判断——如果某个条件为真就做一件事，否则做另一件事（IF–THEN–ELSE）。循环是指重复执行一组指令。循环可由次数控制（重复10次）或由条件控制（重复直到某件事发生）。
- Example of selection: "If it is raining then wear a coat, else wear a t‑shirt."
- 选择示例：“如果下雨就穿外套，否则穿 T 恤。”
- Example of iteration: "Keep stirring until the sugar has dissolved."
- 循环示例：“持续搅拌直到糖溶解。”
12. Testing, Debugging and Logic Errors | 测试、调试与逻辑错误
Even a well‑planned program can have mistakes. Syntax errors happen when you break the rules of the language (like a spelling mistake in code). Logic errors are when the code runs but does the wrong thing – for example, adding two numbers instead of multiplying them. Testing means trying your program with different inputs to find bugs. Debugging is fixing those bugs step by step.
即使规划得再好的程序也可能有错误。语法错误是指你违反了语言规则（比如代码中的拼写错误）。逻辑错误是指代码能运行但做了错误的事——例如，把两数相加而不是相乘。测试就是用不同的输入来试验程序，以发现 bug。调试就是一步步修正这些 bug。
- Always test boundary cases (e.g. the smallest and largest allowed numbers).
- 一定要测试边界情况（如允许的最小和最大数字）。
- Reading your code aloud and using trace tables can help spot logic errors.
- 大声读出你的代码并使用跟踪表有助于发现逻辑错误。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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