Download Igcse Cs Paper 1 2026 HTTP - hypertext transfer protocol and more Exams Information and Communications Technology (ICT) in PDF only on Docsity!
Igcse Cs Paper 1 2023
HTTP - hypertext transfer protocol - correct answer a set of rules which must be followed when transferring files across the internet URL - uniform resource locator - correct answer used to find/identify a webpage on the internet 1. webserver name 2. file name 3. protocol web browser - correct answer software that allows a user to display a webpage on their screen - they interpret html code and show the result actuator - correct answer used in many control operations involving sensors and ADC/DACs. Electromagnetic device eg. motor that outputs result of sensor operation loudspeaker - correct answer output device that produces sound using voltages at different levels which vibrate a cone in speaker housing LED - correct answer Used for backlighting a monitor/tv - they are thin, produce a white light, and do not require much power CCFL - correct answer Old technology used for backlighting - took time to warm up, and produced yellow-ish lighting + required a lot of power volatile - correct answer memory that loses its contents when the power is off eg. main memory
non-volatile - correct answer memory that doesn't lose its contents when the power is off e.g. hard disk off-line storage - correct answer storage that can be physically moved away from a device and stored somewhere else e.g. CD, USB stick, DVD SRAM - correct answer type of RAM that has 'flip flops' to hold each bit of memory. Does not need constant refreshing. magnetic media - correct answer secondary storage with mechanical parts which move over the surface to read and write data magnetically e.g. a hard disk, tape or floppy disk program - correct answer our way of telling a computer what to do, how to do it, and when to do it assembly language - correct answer code that is specific to a particular hardware, but needs to be translated into machine code before it can run machine code - correct answer the binary code that is specific to a machine and does not need translating in order to run translator - correct answer program that changes higher level language into machine code
Denial of Service (DoS) attack - correct answer attempting to prevent a user from accessing part of a network (usually the server); this is usually temporary, but may be very damaging, or a big security breach. overloads web traffic by sending thousands of requests. free software - correct answer software that is free to run, copy, change or adapt, and share with friends, family or colleagues. CSS - correct answer Cascading Style Sheet. Controls presentation of page. Enable multiple pages or elements on a page to be changed in one go. Gigabyte (GB) - correct answer 1024 megabytes. 2 to the power of 30 bytes. HTML - correct answer HyperText Mark-up Language. Used to write and develop webpages to present text. Uses tags. Terabyte (TB) - correct answer 1024 gigabytes. 2 to the power of 40 bytes. Lossless image compression - correct answer Find groups of repeating data. Records the data once and the number of times it was repeated. Lossless text compression - correct answer Finds patterns in original text. Encodes each pattern in a dictionary
PNG - correct answer Lossless picture file format that uses alpha channel to keep transparent backgrounds. MIDI - correct answer A set of instructions for digital instruments to play synthesised sounds. Musical Instrument Digital Interface. .WAV - correct answer uncompressed music files .FLAC - correct answer lossless compressed music files Parity bit - correct answer Set to 1 or 0. Sent with a byte of data to make the total number of 1s odd or even for each byte. 1KB (kilobyte) - correct answer 1,024 bytes (2¹⁰ bits) 1MB (megabyte) - correct answer (2²⁰ bits) 1GB (gigabyte) - correct answer (2³⁰ bits) 1TB (terabyte) - correct answer (2⁴⁰ bits) 1PB (petabyte) - correct answer (2⁵⁰ bits) A - correct answer 10
and then transmitted. Value recalculated at the end to make sure they match. If they don't match, an error has occurred. Echo Check - correct answer Data sent to and from another device twice. Sender compares 2 sets of data, if the sets of data are different, an error has occurred. Wardriving - correct answer Using wireless internet connections illegally through a portable device Secure Sockets Layer (SSL) - correct answer When a user logs onto a website, it encrypts the data. Only the user's computer + web server can make sense of what's being said. A green padlock in the status bar. Record Protocol - correct answer Can be used with or without encryption Handshake Protocol - correct answer Permits the website and user to authenticate and make use of encryption algorithms which only the user and website know. Encryption - correct answer Makes data meaningless unless recipient has the decryption key Asymmetric Encryption - correct answer Private and public key are both needed. Encryption keys generated using a hashing algorithm.
Authentication - correct answer Used to verify data is coming from a trusted source. MAC address - correct answer a number that uniquely identifies a device on the Internet. Often refers to network card. Rarely changed. ISP (internet service provider) - correct answer company charging monthly fee that provides internet access IP (internet protocol) address - correct answer assigned by ISP, unique to each internet session MAC address - correct answer number which uniquely identifies a device
- 1st half = manufacturer, 2nd = device itself - made up of 6 groups of hex digits HTML Presentation - correct answer how the document looks/sounds HTTPS - correct answer a SECURE set of rules which must be followed when transferring files across the internet OLED - correct answer new technology used for tv/monitor screens, using a cathode and anode. Flexible, no backlighting required.
solid state/flash memory - correct answer secondary storage with no moving parts; used in memory sticks, cameras and phones FAT - file allocation table - correct answer a map of where each file is and which sectors on the magnetic disk are free high level language - correct answer portable language designed with the programmer in mind - it is easy to understand and debug, but it needs to be translated in order for a computer to understand it low level language - correct answer language relating to specific architecture and hardware of a particular device - can refer to assembly lang or machine code interpreter - correct answer this translates HLL into machine code one line at a time. assembler - correct answer this translates assembly language into machine code. Once it has done this, the machine code can be used multiple time without translating it again. wardriving - correct answer stealing someone's WiFi spyware/key logging software - correct answer hardware or software that can be used to monitor key presses and gain information.
SSL - correct answer this is used on web browsers to allow data to be sent/received securely. It encrypts data so that only the sender and receiver can understand the information being transmitted symmetric encryption - correct answer this uses a secret key, applied to the message, file that could be a combination of characters. The same key is needed by both sender and receiver to encrypt and decrypt the message asymmetric encryption - correct answer this is a type of encryption using both a public and a private key. The public key can be seen by anyone, and used to encrypt messages to the receiver. The private key is used by the receiver to decrypt the message sent to them. plain text - correct answer text/data before it has gone through encryption algorithm cypher text - correct answer output from encryption algorithm authentication - correct answer used to verify that data comes from a reliable source; used with encryption to strengthen internet security computer ethics - correct answer this considers 3 factors; intellectual property rights, privacy issues, and a computer's effect on society. It is a set of principles that regulates the use of a computer
Full-Duplex Data Transmission - correct answer Data can be sent in both directions at the same time. Half-Duplex Data Transmission - correct answer Data can be sent in both directions but only one at a time. e.g. walkie talkies HTTP(S) - correct answer A set of rules to be followed when transferring files across the Internet. The S is for secure with private data. IP Address - correct answer A number assigned to each device on the Internet. Assigned by ISP. Changes with location. Kilobyte (KB) - correct answer 1024 bytes. 2 to the power of 10 bytes Megabyte (MB) - correct answer 1024 kilobytes. 2 to the power of 20 bytes Memory Dump - correct answer Output of memory contents onto the printer or screen. Usually represented in hexadecimal. Petabyte (PB) - correct answer 1024 terabytes. 2 to the power of 50 bytes Serial Data Transmission - correct answer Data is sent one bit at a time over a single channel/wire. Good over longer distances.
URL - correct answer Web address. Consists of protocol, web server name and file name. Virus - correct answer program/software that replicates/copies itself
- can delete or alter files/data stored on a computer
- can make the computer "crash"/run slow Pharming - correct answer Malicious code installed on a user's hard drive or on the web server; the code will send the user to a fake/bogus website without their knowledge - used to gain personal information Phishing - correct answer Sending out a legitimate-looking email. When the recipient clicks on a link in the email, they are sent to a bogus/fake website - used to gain personal information Wardriving - correct answer To locate and use wireless internet connections illegally. Needs a laptop, wireless network card and an antenna to pick up the signals. Data Bus - correct answer Carries data between the processor, the memory unit and the input/output devices. Bi-directional. .FLAC - correct answer Lossless compressed music files
Keyboard - correct answer Each character pressed is converted into a digital signal interpreted by the computer. RSI can result from too much use. OCR - correct answer Used with scanners to convert scanned text into a text file format. Resistive (Touch)Screen - correct answer One upper layer of polyester and a bottom layer of glass. When top layer is touched it completes a circuit which is interpreted by a microprocessor to determine the co- ordinates. Allows multi-touch. RSI - correct answer An injury created by frequently using devices like a keyboard. Trackerball - correct answer A pointing device where a ball on top of the device moves the cursor. Ideal for environments with little space. Users are less likely to suffer injuries such as RSI. Mouse - correct answer A pointing device which is moved around an area by a user. Denary System - correct answer Number system with base 10 Binary System - correct answer Number system with base 2
Hexadecimal System - correct answer Number system with base 16. Asynchronous Data Transmission - correct answer The data is transmitted in an agreed bit pattern using control bits Synchronous Data Transmission - correct answer A continuous stream of data which is accompanied by timing signals generated by an internal clock Logic Gates - correct answer These take in binary inputs and produce a binary output using gates to regulate the output Logic Circuits - correct answer These are made up of several logic gates and are designed to carry out a specific function. Truth Tables - correct answer Logically work out the output of a logic circuit by writing a table. Actuator - correct answer An electromechanical device used in control applications with sensors. Examples would be relay, solenoid or a motor. Additive Manufacturing - correct answer Used by 3D printers to build up an object layer by layer. Binder 3D Printing - correct answer Using a type of glue to stick together layers in a 3D printer
What is the definition of an Input Device? - correct answer Any device that allows a computer to receive data from the outside world What type of scanner is used at airports to read passport pages? - correct answer 2D Scanners What type of scanner uses gamma rays? - correct answer SPCET Scanners How many times more data (approximately) can a QR code hold compared to a barcode? - correct answer 200 What are 3 automatic adjustments that a microprocessor in a digital camera make? - correct answer Shutter speed, aperture size, size of image What is the name of the cell that light passes through the lens onto in a digital camera? - correct answer Light-sensitive cell What determines the file size of a photograph? - correct answer Number of pixels What are two external factors that affect the quality of the photograph? - correct answer Type of lens and lighting What do most computer systems use to prevent the microprocessor waiting for keys to be pressed? - correct answer Keyboard buffer
What injury are users prone to who do a lot of typing? - correct answer Repetitive Strain Injury (RSI) What are the two most common pointing devices? - correct answer Mouse and trackerball What is the most common environment for where trackerballs are used? - correct answer Control rooms What are the 3 types of touchscreen? - correct answer Capacitive, Infra- red, Resistive What are the most common types of sensors? - correct answer Monitoring and Control What component of a machine is responsible for controlling systems in control applications? - correct answer Actuators What are two ways that control sensors are used on the street? - correct answer Street lighting and traffic light control Benefits of high level languages? - correct answer Easier to read and understand as the language is closer to human language, easier to write in a shorter time, easier to debug at the development stage, easier to maintain once in use
