System Software and Application Software
AdvancedSoftware falls into system software and application software: the operating system manages hardware and provides the user interface as the bridge between them; applications do users' specific tasks; utilities and device drivers maintain the system and drive hardware. Telling the categories and functions apart is the key to understanding how a computer works.
- Software divides into system software, which manages the computer, and application software, which serves user tasks
- The operating system manages hardware below and supports applications above — the most important system software
- Five OS functions: user interface, processor management, memory management, file management, device management
文體小知識：科技知識說明文——講解系統軟件與應用軟件的分類，操作系統的五大功能，以及實用軟件和驅動程式的角色。
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1Software is the programs and data that instruct a computer, in two broad classes. System software manages the computer itself — the operating system, utilities, device drivers and firmware; application software helps users do specific tasks — word processing, spreadsheets, browsers and messaging apps. System software faces the machine, applications face the user; both are indispensable, and exam questions often ask for a software list to be classified correctly.
2The operating system is the most important system software, loaded at start-up and running until shutdown. Downward it manages the processor, memory, storage and input/output devices; upward it provides the environment and services applications run on. Without an operating system, applications would have no way to command the hardware; that one machine can run many programs at once without interference is entirely thanks to the operating system allocating and coordinating resources behind the scenes.
3The operating system's five main functions: first, providing the user interface — a graphical user interface works through windows and icons, a command line interface through typed commands; second, processor management, sharing processor time among programs through multitasking; third, memory management, allocating and reclaiming memory for each program; fourth, file management, organising files in folders and handling access; fifth, device management, commanding the hardware through drivers.
4Utilities maintain and optimise the system — defragmentation software tidies scattered files, antivirus software scans for malware, backup software copies important files. Device drivers let the operating system understand specific hardware: a printer driver turns documents into commands the printer understands; newly connected hardware often needs its driver installed before it works, while drivers for common devices are already built in.
1Summary 重點摘要
Software falls into system software and application software: the operating system manages hardware and provides the user interface as the bridge between them; applications do users' specific tasks; utilities and device drivers maintain the system and drive hardware. Telling the categories and functions apart is the key to understanding how a computer works.
2Vocabulary cards Vocabulary
The programs and data that instruct a computer what to do.
Software that manages the computer itself, including the operating system, utilities and drivers.
Software that helps users perform specific tasks, such as word processing and spreadsheets.
The core system software that manages hardware resources and provides the platform applications run on.
An interface using windows, icons and pointers so users operate by clicking.
An interface where users type text commands to control the computer — precise and fast but requiring syntax.
The operating system sharing processor time among programs so they appear to run at once.
System software that maintains and optimises the computer, such as antivirus, backup and defragmentation tools.
Software that lets the operating system control a specific hardware device.
A utility that rearranges scattered file fragments into contiguous space to speed up reading.
3Step by step Steps
- Step 1: The two classes of softwareSoftware is classified by whom it serves: system software manages the computer itself, application software does the user's tasks. For example, on one machine the operating system and antivirus software are system software, while a word processor and a browser are applications. A common question lists software for classification; the key question is: does it serve the computer system, or the user's specific task?
- Step 2: The operating system as bridgeThe operating system manages hardware below and serves applications above — the bridge between them. For example, when printing a document, the word processor never commands the printer directly; it asks the operating system, which orders the printer through its driver. If two programs request printing together, the operating system also sequences the jobs so pages do not interleave.
- Step 3: The user interfaceThe operating system offers two ways for people to talk to the machine: a graphical user interface with windows, icons and menus — intuitive and easy to learn — and a command line interface of typed commands — precise and fast once the syntax is learned. For example, an ordinary user opens a file by clicking its icon; an administrator renames hundreds of files in one command line. Each has its strengths.
- Step 4: Processor management and multitaskingThe operating system slices processor time into tiny pieces and hands them out in turn, so several programs appear to run at once — multitasking. For example, listening to online music while writing a report, the processor switches rapidly between the player and the word processor, unnoticed by the user; if a runaway program hogs the processor, the operating system can force it to close, protecting the rest.
- Step 5: Memory and file managementThe operating system allocates memory to each program, reclaims it when the program ends, and stops programs intruding on one another; file management organises files in a folder tree and handles naming, access rights and deletion. For example, saving a report — choosing a folder, naming it, confirming — is the operating system finding space on the disk; when a program crashes, the system reclaims its memory and carries on.
- Step 6: Device management and driversEach kind of hardware speaks a different command language, and drivers translate: the operating system issues general instructions, the driver turns them into device-specific commands. For example, a newly connected printer appears in the print list only after its driver is installed; drivers for common devices like keyboards and mice are built in, so they work the moment they are plugged in — the basis of plug and play.
- Step 7: Maintenance by utilitiesUtilities keep the system healthy: antivirus software scans and removes malware, backup software copies important files on schedule, defragmentation software rearranges scattered file fragments into contiguous space for faster reading. For example, after years of use a hard disk scatters files everywhere and slows down; defragmentation restores the speed — and regular backups mean a failed disk does not cost everything.
5Worked example Example
Ming meets five everyday scenes on his computer: 1) playing music while writing a report; 2) sorting downloaded photos into folders; 3) a new mouse working the moment it is connected; 4) two programs running side by side without interference; 5) closing a window by clicking its icon. Identify which operating system function each scene illustrates.
- Scene 1: processor time is shared between the player and the word processor — processor management through multitasking.
- Scene 2: sorting photos into folders, naming and moving files — file management.
- Scene 3: the new mouse works at once because the operating system identifies and manages the device through its driver — device management.
- Scene 4: the two programs each occupy independent memory without interfering — memory management.
- Scene 5: clicking icons to operate windows — the graphical user interface provided by the operating system.
- Answer: The five scenes map onto the operating system's five functions in order: processor management (multitasking lets music and the report run together), file management (photos organised in folders), device management (the driver makes the new mouse plug and play), memory management (each program has independent memory), and the user interface (the GUI supports clicking). The technique for matching questions: memorise the five function names, then fit each scene's action to one, answering in functional terms.
6Common mistakes Mistakes
7Quick check Quick check
Q1What is the main difference between system software and application software?
Q2State the five main functions of an operating system.
Q3What are the characteristics of a GUI and a command line interface?
Q4A newly connected printer cannot print. What is most likely missing?
Q5What does defragmentation software do?
8Recap Recap
- Software divides into system software, which manages the computer, and application software, which serves user tasks
- The operating system manages hardware below and supports applications above — the most important system software
- Five OS functions: user interface, processor management, memory management, file management, device management
- Multitasking shares processor time in rapid turns so programs appear to run at once
- Drivers translate between the OS and hardware; utilities handle antivirus, backup and defragmentation