📚 Year 7 AQA Computer Science: Core Knowledge Review | Year 7 AQA 计算机：核心知识点梳理
In Year 7, the AQA Computer Science curriculum introduces students to the essential building blocks of computing. This article summarises the core knowledge areas, from hardware and software to programming, binary, networks and online safety, helping you consolidate your understanding and prepare for assessments with confidence.
在七年级，AQA 计算机课程向学生介绍计算的基本构件。本文梳理了核心知识领域，涵盖硬件、软件、编程、二进制、网络和网络安全，帮助你巩固理解，自信备考。
1. Computer Hardware Basics | 计算机硬件基础
Hardware refers to the physical components of a computer system that you can touch. The central processing unit (CPU) is often called the 'brain' of the computer because it carries out instructions. The motherboard connects all the components together, while random access memory (RAM) provides temporary storage for data and programs currently in use.
硬件指计算机系统中可以触摸的物理部件。中央处理器(CPU)常被称为计算机的“大脑”，因为它负责执行指令。主板将所有部件连接在一起，而随机存取存储器(RAM)则为当前使用的数据和程序提供临时存储。
Long-term storage is provided by devices such as hard disk drives (HDD) and solid state drives (SSD). The power supply unit delivers electricity, and cooling fans prevent overheating. Understanding these parts helps you appreciate how a computer works at a physical level.
长期存储由硬盘驱动器(HDD)和固态驱动器(SSD)等设备提供。电源单元提供电力，冷却风扇防止过热。了解这些部件有助于你从物理层面理解计算机的工作原理。
2. Software: System and Application | 软件：系统软件与应用软件
Software is a set of instructions that tells the hardware what to do. System software includes the operating system (e.g. Windows, macOS, Linux), which manages hardware resources, provides a user interface and allows other software to run. Utility programs perform maintenance tasks like antivirus scanning and disk cleanup.
软件是一组告诉硬件该做什么的指令。系统软件包括操作系统(如Windows、macOS、Linux)，它管理硬件资源、提供用户界面并允许其他软件运行。实用程序执行维护任务，如防病毒扫描和磁盘清理。
Application software lets users perform specific tasks: word processors create documents, spreadsheets manage numbers, web browsers access the internet, and games provide entertainment. Unlike system software, applications depend on the operating system to function.
应用软件让用户执行特定任务：文字处理程序创建文档，电子表格管理数字，网页浏览器访问互联网，游戏提供娱乐。与系统软件不同，应用程序依赖操作系统才能运行。
3. Input and Output Devices | 输入与输出设备
Input devices send data into the computer. Keyboards allow text entry, mice control pointers, touchscreens accept finger gestures, microphones capture sound, and scanners convert physical documents into digital form. Sensors like thermometers and motion detectors are also input devices.
输入设备将数据送入计算机。键盘用于文字输入，鼠标控制指针，触摸屏接受手指手势，麦克风捕获声音，扫描仪将纸质文档转换为数字形式。温度计和运动检测器等传感器也是输入设备。
Output devices present information from the computer to the user. Monitors display images and text, speakers produce audio, printers create hard copies on paper, and projectors show large-scale visuals. Some devices, such as a touchscreen or a headset with microphone, can act as both input and output.
输出设备将计算机中的信息呈现给用户。显示器显示图像和文本，扬声器发出声音，打印机在纸上创建硬拷贝，投影仪显示大尺寸影像。某些设备，如触摸屏或带麦克风的耳机，可以同时充当输入和输出设备。
4. Storage Devices and Units | 存储设备与单位
Storage is measured in bytes. A single byte can store one character, like 'A' n computing, binary definitions exist but the decimal system is common for storage labels.
存储以字节为单位。一个字节可以存储一个字符，如'A'。更大的单位遵循1 000的幂：千字节(KB)=1 000字节，兆字节(MB)=1 000 KB，吉字节(GB)=1 000 MB，太字节(TB)=1 000 GB。计算中也有二进制定义，但十进制常用于存储标签。
Magnetic storage (e.g. HDD) uses magnetised platters, offering large capacity at lower cost. Solid state storage (e.g. SSD, USB flash drive) has no moving parts, making it faster and more durable. Optical storage (e.g. CD, DVD, Blu-ray) uses lasers to read data and is often used for media distribution.
磁性存储(如HDD)使用磁化盘片，以较低成本提供大容量。固态存储(如SSD、U盘)没有移动部件，更快且更耐用。光存储(如CD、DVD、蓝光)使用激光读取数据，常用于媒体分发。
5. Binary and Data Representation | 二进制与数据表示
Computers use binary, a base‑2 number system with only two digits: 0 and 1. Each binary digit is called a bit. Eight bits form a byte. Because electronic circuits can easily represent two states (on/off), binary is the natural language of computers. All data — text, images, sound — is stored as sequences of bits.
计算机使用二进制，一种只有0和1两个数字的基数为2的数字系统。每个二进制数字称为一个位(bit)。八个位构成一个字节(byte)。由于电子电路可轻松表示两种状态(开/关)，二进制是计算机的自然语言。所有数据——文本、图像、声音——都存储为位序列。
Text is encoded using systems like ASCII, where each character has a unique 7‑bit or 8‑bit binary code (e.g. 'A' is 0100 0001). Images are made of pixels: each pixel’s colour is represented by binary numbers for red, green and blue values. Higher colour depth means more bits per pixel, resulting in a wider range of colours but larger file sizes.
文本使用如ASCII的系统编码，每个字符有一个唯一的7位或8位二进制代码(例如'A'为0100 0001)。图像由像素构成：每个像素的颜色由红、绿、蓝值的二进制数表示。更高的颜色深度意味着每像素更多位，颜色范围更广但文件更大。
6. Introduction to Algorithms | 算法入门
An algorithm is a step‑by‑step set of instructions to solve a problem or complete a task, just like a recipe. Algorithms must be precise, unambiguous, and have a clear end point. Examples include a method to sort a list of names into alphabetical order or a sequence of moves to guide a robot through a maze.
算法是一套逐步解决问题的指令，就像食谱一样。算法必须精确、无歧义且有明确的终点。示例包括将姓名列表按字母顺序排序的方法，或引导机器人走出迷宫的移动序列。
We can express algorithms using flowcharts (shapes like ovals for start/end, rectangles for processes, diamonds for decisions) or pseudocode (structured English‑like statements). Understanding how to design and test algorithms is a core skill in computer science because programs are just algorithms written in a programming language.
我们可以使用流程图(椭圆表示开始/结束，矩形表示处理，菱形表示判断)或伪代码(类似英语的结构化语句)来表达算法。理解如何设计和测试算法是计算机科学的核心技能，因为程序就是用编程语言写成的算法。
7. Programming Basics: Sequence, Selection and Iteration | 编程基础：顺序、选择与循环
All programs are built from three fundamental control structures: sequence, selection and iteration. Sequence means executing instructions one after another in order. For example, asking for a user’s name and then printing a greeting.
所有程序都建立在三种基本控制结构上：顺序、选择和循环。顺序指按顺序一条接一条地执行指令。例如，要求用户输入姓名，然后打印问候语。
Selection allows the program to make decisions, often using IF…THEN…ELSE statements. 'IF score ≥ 50 THEN output "Pass" ELSE output "Fail".' g as a condition is true. These structures apply across languages like Scratch and Python.
选择允许程序做出决策，通常使用IF…THEN…ELSE 语句。'IF 分数 ≥ 50 THEN 输出"及格" ELSE 输出"不及格"。'循环重复一个代码块：FOR 循环运行指定次数，而WHILE 循环在条件为真时持续运行。这些结构适用于Scratch和Python等语言。
8. Introduction to Networks | 网络入门
A network is two or more computers connected together to share resources. A local area network (LAN) covers a small geographical area like a school or home, and often uses Ethernet cables or Wi‑Fi. A wide area network (WAN) connects LANs across cities or countries; the internet is the largest WAN.
网络是两台或更多连接在一起以共享资源的计算机。局域网(LAN)覆盖小地理区域，如学校或家庭，通常使用以太网电缆或Wi‑Fi。广域网(WAN)连接城市或国家间的局域网；互联网是最大的广域网。
The World Wide Web is not the same as the internet. The web is a collection of web pages accessed via the internet using a browser. Key networking concepts include IP addresses that identify devices, DNS that translates domain names into IP addresses, and protocols like HTTP/HTTPS that define rules for data transfer.
万维网并不等同于互联网。网页是通过浏览器经由互联网访问的网页集合。关键的组网概念包括识别设备的IP地址、将域名转换为IP地址的DNS，以及定义数据传输规则的HTTP/HTTPS等协议。
9. Staying Safe Online | 安全上网
Cybersecurity involves protecting systems, networks and data from digital attacks. Common threats include malware (viruses, worms, trojans) that can damage files or steal information, phishing emails that trick users into revealing passwords, and social engineering that manipulates people into giving away private data.
网络安全涉及保护系统、网络和数据免受数字攻击。常见威胁包括可破坏文件或窃取信息的恶意软件(病毒、蠕虫、特洛伊木马)、诱骗用户透露密码的网络钓鱼邮件，以及操纵人们泄露私人数据的社会工程学。
To stay safe, use strong passwords — a mix of letters, numbers and symbols — and don’t reuse them across accounts. Keep software updated to fix security holes. Beware of suspicious links in messages, think before sharing personal information, and always log out on shared devices. Encrypting sensitive data and using two‑factor authentication add extra layers of protection.
为保持安全，请使用强密码——字母、数字和符号的组合——并且不要在不同帐户间重复使用。保持软件更新以修复安全漏洞。警惕消息中的可疑链接，分享个人信息前要三思，在共享设备上始终注销。加密敏感数据和使用双因素认证可增加额外的保护层。
10. Computational Thinking | 计算思维
Computational thinking is a problem‑solving approach that uses concepts fundamental to computer science. Decomposition breaks a large problem into smaller, more manageable parts — like dividing a game design task into graphics, scoring and controls. Pattern recognition looks for similarities between problems to reuse solutions.
计算思维是一种运用计算机科学基本概念的问题解决方法。分解是将一个大问题拆分成更小、更易管理的部分——例如将游戏设计任务分为图形、计分和控制。模式识别寻找问题之间的相似之处，以重用解决方案。
Abstraction focuses on the important information only, ignoring irrelevant details, such as representing a library member by name and ID rather than their entire life story. Algorithmic design then creates a step‑by‑step plan for the solution. These stages together help you tackle complex tasks logically and efficiently in all areas of computing.
抽象只关注重要信息，忽略无关细节，例如用姓名和ID表示图书馆成员，而非其全部生活故事。算法设计则创建解决方案的逐步计划。这些阶段共同帮助你在所有计算领域中有逻辑且高效地处理复杂任务。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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