Operating systems and utility software
| English | Chinese | Pinyin |
|---|---|---|
| operating system | 操作系统 | cāo zuò xì tǒng |
| process management | 进程管理 | jìn chéng guǎn lǐ |
| process | 进程 | jìn chéng |
| memory management | 内存管理 | nèi cún guǎn lǐ |
| virtual memory | 虚拟内存 | xū nǐ nèi cún |
| paging | 分页 | fēn yè |
| device drivers | 设备驱动程序 | shè bèi qū dòng chéng xù |
| disk defragmenter | 碎片整理 | suì piàn zhěng lǐ |
The software that runs everything
- On its own, hardware only fetches and runs instructions — it knows nothing of files, programs or users.
- The operating system 操作系统 is the software layer that manages it all.
- It also bundles utility programs to keep the system healthy.
What an operating system does
- Manages the hardware (processor, memory, I/O, storage) for the running programs.
- Provides services (file system, network, accounts) through a clear interface, so programs don't talk to hardware directly.
- Provides a user interface (command line, GUI, touch).
- Lets several programs share the hardware safely — each gets fair CPU time and is kept out of the others' memory.
The main jobs the operating system manages
Where the operating system sits
Tap each layer. The OS is the middle layer — it sits between your applications and the hardware, sharing the machine safely so programs never touch the hardware directly.
Which is a core job of an operating system?
The OS manages hardware and provides services and a UI, letting multiple programs run safely on shared hardware.
The operating system lets several programs share the same hardware safely, so they don't interfere with each other.
Sharing the CPU, memory and devices safely between many programs is exactly what the OS is for.
Key management tasks
- Process management 进程管理 — load programs, schedule them on the CPU, switch between them. (A running program is a process 进程.)
- Memory management 内存管理 — give memory to processes, keep them apart, and use virtual memory 虚拟内存 / paging 分页 so the working set can exceed physical RAM.
- File management — organise files/folders on storage, control permissions.
- Device management — handle I/O via device drivers 设备驱动程序, buffer data, manage interrupts.
- Plus security (accounts, permissions, firewall) and networking.
A desktop operating system manages the screen, files and programs for the user.
Memory management keeps each process in its own block of memory, so one program can't corrupt another.
A running program is called a:
Process management loads, schedules and switches between processes (running programs).
Match each OS management task to what it does.
The OS juggles four core resources — the CPU (processes), RAM (memory), storage (files) and peripherals (devices).
Virtual memory (paging) lets the OS:
Paging moves blocks between RAM and disk so programs can use more memory than is physically installed.
Utility software
- Disk defragmenter 碎片整理 — gathers the pieces of fragmented files together on a hard disk to cut seek time (not useful on SSDs).
- Backup — copies data elsewhere for recovery.
- Antivirus — scans for malware and quarantines threats; firewall — filters network traffic.
- Compression, system monitors and updates round it out.
A smartphone runs a mobile operating system such as Android.
- Utility software: disk formatter, defragmentation software, disk contents analysis / disk repair software, back-up software, virus checker and file compression. The OS also does hardware management; a Dynamic Link Library (DLL) is shared code loaded at run time.
A disk defragmenter is useful on a hard disk but NOT on an SSD because:
Defragmenting reduces head-movement (seek) time on a spinning disk; an SSD has no heads, so it gains nothing (and the extra writes wear it).
System-maintenance programs such as antivirus, backup and defragmenter are called ______ software.
Utility software maintains the system; word processors and browsers are application software.
You've got it
- the OS manages hardware, provides services + a UI, and lets programs share the hardware safely
- core tasks: process, memory (virtual memory/paging), file, device (drivers), security
- virtual memory lets the working set exceed physical RAM
- utilities: defragmenter (HDD only), backup, antivirus, firewall, compression