ICT IGCSE Topic 1 - Types and components of a computer system

1.5.4 - Quantum cryptography

Is the science of making a message unintelligible to any unauthorised user (a hacker). This technique is often referred to as encryption.

1.4.3 - Tablets Describe the characteristics of a tablet computer and what it is used for

● high-definition, anti-glare displays ● front- and back-facing cameras (which are used to take photos and videos, or act as a webcam when doing video calls over the internet) ● lower weight and longer battery life than laptops ● Bluetooth connection to printers and other devices ● make use of flash (solid state) memory and cloud storage facilities to backup and synchronise (often just referred to as 'sync') data sources ● they use a number of sensors to carry out the following functions: • proximity sensors to detect if the device is close to, for example, the ear (which allows it to block unintended 'touches') • accelerometer, which detects movement and orientation of the device (for example, moving the display from portrait to landscape to view videos, or to allow it to be used as a 'steering wheel' in car-racing games)

1.4.4 - Smartphones Describe characteristics Describe advantages and disadvantages of a smartphone

● send/receive emails ● surf the net (for example, so you can order goods on the move) ● global positioning system (use of maps to navigate to a location) ● calendar functions ● telephone banking (send and receive money using banking Apps) Adv- ● they are very small in size and lightweight - therefore very easy to carry round and have on your person at all times (this is more difficult with laptops since they are much bulkier and also much heavier) ● can use them to make phone calls as well as connect to the internet while on the move Dis- ● web browsing and photography can drain the battery quickly ● memory size in most phones isn't very large when compared to laptops and PCs - although it is comparable with tablets

1.1 - Hardware and software a) Give examples of external hardware b) Give examples of internal hardware

a) Keyboard, mouse, monitors, and printers. b) Processor, motherboards, random access memory (RAM), read-only memory (ROM), video cards, sound cards and internal hard disk drives.

1.5 - describe how artificial intelligence biometrics are having an impact on everyday life

> AI biometrics overcomes this problem by using dynamic profiling - the system learns by using AI about a person's fingerprints on every scan a) This means a person doesn't have to worry about getting their finger in exactly the right place every time on the scanner. b) The system learns from the different alignments so it is still able to match the fingerprints to those stored on a database. > New systems use AI to learn from scanning a number of faces and can pick out these soft biometric features. a) This means the system can still recognise faces and cross-reference these attributes with corresponding images stored on the database.

1.4.2 - Laptop Describe the advantages and disadvantages of a laptop computer (vs. desktop computers)

Advantages ● the most obvious is their portability; they can be taken anywhere since the monitor, pointing device, keyboard, processor and backing store units are all together in one single unit ● because everything is in one single unit, there are no trailing wires, etc. ● they can take full advantage of Wi-Fi ● since they are portable, they can link into any multimedia system. Disadvantages ● since they are easily portable, they are also easier to steal ● they have limited battery life, so the user may need to carry a heavy adaptor ● the keyboards and pointing devices can sometimes be awkward to use.

1.4 - Types of computer 1.4.1 - PC/desktop Advantages and disadvantages of desktop computers over laptop computers

Advantages- ● spare parts and connections tend to be standardised, which usually results in lower costs. ● the desktop has a better specification (for example, a faster processor) for a given price (often due to size and construction constraints in laptops). ● power consumption is not critical since they usually plug straight into a wall socket and the larger casings allow a better dissipation of any heat build-up. ● because they are usually fixed in one location, there is less likelihood of them being damaged. ● internet access is more stable since they are not moved around (the user will always have the same data transfer rate). Disadvantages- ● not particularly portable since they are made up of separate components. ● because they are not portable, it is necessary to copy files, etc. when you want to do some work elsewhere (for example, at home) - with a laptop you simply take the whole computer with you. ● more complicated since all the components (for example, keyboard, mouse) need to be carried around with you and then connected to the computer by wires or wireless connections, which also clutters up the desk space.

1.4.3 - Tablets Describe advantages and disadvantages of a tablet computer (vs. laptops)

Advantages- ● very fast to switch on (no time delay waiting for the 'windows' system to load up) ● fully portable - they are so lightweight that they can be carried anywhere Disadvantages- ● they often have limited memory or storage ● they can be expensive to run if the internet is being accessed frequently via 3G/4G/5G mobile phone networks ● typing on a touchscreen can be slow and error-prone compared to a standard keyboard

1.3.1 - User interfaces Explain GUI What are the advantages and disadvantages?

Allows the user to interact with a computer using pictures or icons rather than having to type in a number of commands Adv- User doesn't need to learn any commands. User-friendly, very simple. Dis- Uses up more memory than CLI. The user is limited to the icons provided on the screen. Needs an operating system, such as windows to operate (e.g windows), uses a lot of memory.

1.1 - Hardware and software Define hardware and what can hardware be

General term for the physical components that make up a computer system. Hardware can either be external or internal.

1.5.7 - Virtual reality

Is an artificial environment created by software. The user makes use of data goggles, sensor suits, data gloves or helmets to get a feeling of reality (that is, the feeling of 'being there').

1.3.1 - User interfaces What does CLI require the user to do? What are the advantages and disadvantages?

It requires the user to type in instructions to choose options from menus, open software and so on. Adv- User is in direct communication with the computer. Not restricted to a number of predetermined options. Dis- Complex method, slow difficult to edit. Good for programmer, analyst of technicians.

1.2 - Main components of a computer system Name 4 internal hardware devices and define them

The CPU (central processing unit - found on the motherboard)- it interprets and executes the commands from the computer hardware and software. Often referred to as the microprocessor. The internal HDD or SSD - is the computers main internal storage, fast data transfer time, stores application software etc. RAM - an internal chip where data is temporarily stored when running applications, volatile memory. ROM - memory used to store information that needs to be permanent, cannot be altered as it is read only and nonvolatile, contains BIOS which tells the computer what to do when it first starts up.

1.3 - Operating systems What do OS's do and what are the general tasks for a typical operating system?

They enable computer systems to function and to allow users to communicate with computer systems. Control of the operation of the input, output and backing storage devices, supervising the loading, running and storage of applications programmes, dealing with errors that occur in application programs, maintaining security, maintaining a computer log, user interface.

1.1 - a) Define software and what are the two types of software. b) What are examples of application software? c) What are examples of system software it?

a) Programs for controlling the operation of a computer or processing of electronic data. The 2 types of software are application and system software. b) Word processing, spreadsheet, database management systems, control software, apps etc. c) Compilers, linkers, device drivers, operating systems and utilities.