A PC (personal computer, パーソナルコンピュータ) is a small computer that one person uses for all kinds of work, such as writing documents and working with spreadsheets.
There are desktop models that sit on a desk and notebook models you can carry around. By changing the software installed, the same machine can serve for office work, study or entertainment.
AnalogyIt is like your own car, which you drive wherever your errands take you.
How to rememberPersonal means "for one person", and the P in PC says exactly that.
Exam points
Mix-upA PC is a machine the user operates directly to get work done, which sets its role apart from a server (サーバ) that answers requests from many users over a network.
A server (サーバ) is a computer whose role is to take requests from other computers (clients, クライアント) over a network and supply them with data or functions.
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Servers are named after what they provide: one that returns web pages is a web server, and one that passes mail along is a mail server. Because they handle many requests without a break, many are built with more processing power and reliability than a PC.
AnalogyIt is like a library's front desk, which brings out the book each visitor asks for.
How to rememberTo serve is to bring people what they ask for, so the machine that does it is a server.
Exam points
ExamA blade server (ブレードサーバ) treats one thin board carrying processing and storage parts as one server and slots many such boards into a shared enclosure (筐体). The enclosure handles power and cooling for all of them, so you can add servers without taking up more space.
Mix-upNames based on the function provided, like web server, and names based on the enclosure's form, like blade server (ブレードサーバ), sort servers along different axes.
A general-purpose computer (mainframe, 汎用コンピュータ / メインフレーム) is a large computer that supports the core business of companies and government offices.
It has the processing power and reliability to work through large volumes of data for long periods without stopping, and is used for work that cannot halt, such as managing bank accounts. The "general-purpose" in its name means it is not limited to one kind of calculation but can run all sorts of business work.
AnalogyIt is like a large power plant that keeps the whole town supplied with electricity.
How to rememberThe Japanese 汎 means "broadly", so 汎用 reads as "broadly used", the same idea as general-purpose.
Exam points
ExamA supercomputer (スーパーコンピュータ) is built to solve huge scientific and engineering calculations at extremely high speed, so its design goal differs from that of a general-purpose computer (汎用コンピュータ), which handles a broad range of business processing.
A smartphone (スマートフォン) is a handheld device that combines a mobile phone's calling function with the abilities of a computer whose functions grow as you add apps (アプリ).
You operate it by touching the screen directly, and one unit packs in networking, a camera and GPS for finding your location. What it can do depends on the apps you install, so it can work as a map or as a way to pay.
AnalogyIt is like a toolbox that fits in your pocket, and you can add tools to it later.
How to rememberSmart means clever, and a smartphone is a phone that got clever.
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Mix-upA conventional mobile phone (携帯電話) relies mainly on built-in functions, whereas a smartphone (スマートフォン) lets the user add apps to widen what it can do, and that is the difference between them.
A tablet device (タブレット端末) is a portable computer whose flat body has a screen across its entire front, operated by touching it with a finger.
Its large screen suits viewing documents, videos and e-books. Since it works without a keyboard, it is also used where people carry it around and show the screen, such as taking orders in a shop or explaining things on a customer visit.
AnalogyIt is like a drawing board you hold up to show a sheet of paper to others.
How to rememberTablet originally meant a flat slab, like a clay or stone tablet, and the device is named after that shape.
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Mix-upSmartphones (スマートフォン) and tablet devices (タブレット端末) are both operated by touch, and they differ mainly in screen size and how easy they are to carry.
A wearable device (ウェアラブル端末) is a small computer you use while wearing it on your body, such as a wristwatch-type or glasses-type device.
Many models, such as watch types, have sensors that measure and record things like your step count and heart rate while you wear them. The measured data is usually sent to a smartphone or similar device to be displayed or stored.
AnalogyIt is like an attendant who stays close by your side and responds the moment you need something.
How to rememberWear plus able: a device you can wear, just like clothing.
Exam points
ExamAn activity tracker (アクティビティトラッカ) is a wearable gadget that uses the sensors in the device you wear to measure and record your daily activity and sleep.
Mix-upA smartphone (スマートフォン) is a device you hold in your hand, while a wearable device (ウェアラブル端末) is one you use while wearing it. The two are told apart by how they are used.
Smart device (スマートデバイス) is an umbrella term for information devices that have networking and apps and are carried around or worn.
Smart device
Smartphone
Tablet device
Wearable device
Other portable information devices
It is not the name of one model but a way of grouping devices together, such as the handheld and wearable devices covered in this unit. Most of them connect to the internet or to other devices and can gain functions through apps.
AnalogyJust as apples and oranges are both called fruit, it is a name one level up.
How to rememberSmart plus device: the same smart as in smartphone.
Exam points
Mix-upSmart device (スマートデバイス) is the higher-level name that groups device types, and smartphones (スマートフォン) and tablet devices (タブレット端末) are individual types that fall under it.
Key points
A server supplies data or functions in response to client requests, and one form, the blade server, saves space by gathering boards into a shared enclosure.
A general-purpose computer (mainframe) is a large machine that runs a company's core business, handling heavy workloads without stopping thanks to its high reliability.
A wearable device is used while worn, and many models measure body movement and condition with sensors.
Smart device is the umbrella term for handheld and wearable devices that have networking and apps.