140 Questions
Question 1
Multiple Choice
Hardware
Question 2
Multiple Choice
Peripheral device
Question 3
Multiple Choice
Human resources
Question 4
Multiple Choice
Client
Question 5
Multiple Choice
Server
Question 6
Multiple Choice
Email server
Question 7
Multiple Choice
DNS (Domain Name Server)
Question 8
Multiple Choice
Router
Question 9
Multiple Choice
Firewall
Question 10
Multiple Choice
Security (Ethical/social issues)
IB Comp Sci Paper 1 Guide
Flashcards generated with inquiziti.com. Cut along the dashed lines. Fold in half on the solid line.
Hardware
Physical, tangible elements of a computer system
Peripheral device
Auxiliary device that can connect to, communicate and work with the computer
Human resources
The set of individuals who make up the workforce of an organisation, business sector or economy
Client
Piece of computer hardware/software that accesses services made available by server, by sending requests to server
Server
Program/host computer that fulfils requests from client programs or computers across network and shares info to clients
Email server
Message transfer agent that transfers electronic messages from one computer to another in a network
DNS (Domain Name Server)
Server that translates web addresses written in letters (more memorable for humans) to the numeric IP (Internet Protocol) address
Router
Connects networks together to forward data packets between networks, deciding where to send information
Firewall
Controls incoming and outgoing network traffic, determining what data packets should be allowed through, based on a rule set
Security (Ethical/social issues)
Protecting hardware, software, peripherals, data and networks from unauthorized access
Privacy (Ethical/social issues)
Controlling how and to what extent data is accessed and used by others
People and machines (Ethical/social issues)
Easier communication, more information and efficiency BUT addiction, real life neglect, lack of sleep, health problems
Digital divide and equality of access (Ethical/social issues)
Inequalities regarding use and access to computer systems in different environments/ countries
Surveillance (Ethical/social issues)
Monitoring people e.g. for law enforcement, employers, traffic control etc.
Globalisation & cultural diversity (Ethical/social issues)
Spread info and reduce political, geographical, financial boundaries. BUT diminishing of traditional cultures
Reliability (Practical issues)
How consistently a computer system functions according to its specifications, with minimal system failure
Standards and protocols (Practical issues)
Rules followed in development of systems, including proprietary standards, industry standards, de facto standards
Central Processing Unit (CPU)
Component of a computer system which interprets/ processes and executes program instructions
Control Unit (CU)
Fetches data/ instructions from memory, decodes it into commands and controls transfer of data/instructions among other units of CPU
Arithmetic Logic Unit (ALU)
Performs arithmetic and logical calculations/operations
Registers
Small, very fast circuits that store intermediate values from calculations or instructions inside the CPU
Memory Address Register (MAR)
Stores address of next instruction to be decoded and executed. Connected to RAM through Address Bus
Memory Data Register (MDR)
Stores data of instruction most recently taken from RAM, i.e. instruction about to be executed. Connected to RAM through Data Bus
Instruction/Machine cycle
Basic operation cycle of computer taking place within certain time period, where instruction is fetched, decoded, executed and stored
Bus
Set of wires that connect two components in a computer system
Primary memory
Only storage directly accessible by CPU
Random Access Memory (RAM)
Stores data and instructions of program currently being run. Data constantly moved and overwritten. RAM is volatile
Read Only Memory (ROM)
Stores permanent instructions and data of programs used to boot and operate the computer. Cannot be overwritten. Non-volatile
Cache memory
Type of memory that is smaller and accessed faster than RAM since closer to the CPU
Secondary memory
Auxiliary storage. Relatively slow but higher capacity than primary memory. Can be written to but non-volatile
Virtual memory
Part of secondary memory used as if it is main memory
Operating system
Set of software that controls computer's hardware resources and provides services for programs
Peripheral communication (Role of OS)
OS controls hardware and provides interface for applications to communicate with peripherals
Memory management (Role of OS)
Manages how memory is used by applications. OS allocates sections of memory to each program being run
Data management (Role of OS)
Accessing and storing data. Keeping track of files and location in memory
Resource allocation (Role of OS)
Manages resources and multitasking so tasks share CPU time, including memory and processor time
Security (Role of OS)
Provides measures such as password authentication, magnetic cards, access rights to prevent unauthorised access
Word processing (Application software)
Producing, editing, formatting and printing of documents
Spreadsheets (Application software)
Data represented by cells, organised in rows and columns. Can perform calculations through formulae
Database Management System (DBMS)
Manages and provides interface for users to use database (organised store of data)
Web browsers
Access, retrieve, present content on WWW. Connects to web servers to request information
Email (Application software)
Exchange of digital messages to email server, recipient receives message when they connect to server
Computer Aided Design (CAD)
Used in engineering, manufacturing and architecture to create, modify and analyse a design
Graphical User Interface (GUI)
Allows user to interact with software in different ways. Includes Toolbar, Menu, Dialogue box
Command Line Interface (CLI)
Where you had to type in commands
Toolbar (GUI feature)
Buttons, icons, menus etc. on it
Menu (GUI feature)
List of commands you can chose
Dialogue box (GUI feature)
Communicates info to user and allows to choose option
Binary digit (bit)
Basic unit of info, 1 or 0. One digit in a binary number
Byte
8 bits
Kilobyte
1024 bytes
Decimal/denary
Positional system that uses 10 digits to represent a number. Base-10
Binary
Uses 2 digits to represent a number. Base-2
Hexadecimal
Positional system that uses 16 digits to represent a number. Base-16
Characters (Data representation)
American Standard Code for Information Interchange (ASCII) character encoding scheme represents text
Colours (Data representation)
Pixels, each one has a colour. Colour value can be represented by hex RGB-6-digit hex number
AND (Logic gate)
2 inputs, output TRUE only if both inputs TRUE
OR (Logic gate)
2 inputs. If either input is true, output is true
NOT (Logic gate)
1 input. Output is inverse of input
NAND (Logic gate)
NOT AND. AND gate but the output is inverted, so when both inputs are TRUE, output is FALSE
NOR (Logic gate)
NOT OR. OR gate but output inverted, so opposite of OR gate. If either input is true, output is false
XOR (exclusive OR) (Logic gate)
Like OR- if either input true, output = TRUE. Except for when both inputs = TRUE, then output = FALSE
Network
Set of computers or computer systems that are interconnected and share resources and data
Node
Device on network
Client (Networking)
Device that requests service from server in the same network
Hub
Connection point for all devices on network, devices connected through Ethernet cables. Data from device goes to the hub, then sent to all devices
Switch
Connection point but can identify which device is connected to which port, so can send data to target device
Router (Networking)
Device that connects network to another e.g. home network to internet
Local Area Network (LAN)
Network devices are connected within limited geographical area, e.g. a room, a home, a school, office building etc.
Virtual Local Area Network (VLAN)
Devices or LANs from different segments in a LAN connected logically, e.g. splitting a hospital LAN into VLANs
Wireless Local Area Network (WLAN)
Connects nodes in limited geographical area but with no wires
Wide Area Network (WAN)
Connects different computer systems or LANs from different geographical areas, can span over a city, country or the world
Storage Area Network (SAN)
Type of LAN designed to handle large data transfers. Each client is connected to a server that provides access to storage devices
Personal Area Network (PAN)
Network covering individual's working area, very small space. e.g. PC, phone, tablet sharing data
Peer-to-Peer Network (P2P)
Different to client-server, no centralised server. All nodes have equal privileges and responsibility
Internet
A WAN. Connect to it through internet service provider (ISP) for monthly fee
Extranet
External extension to a LAN- Part of a network that uses internet protocols to allow controlled access by specific users
Virtual Private Network (VPN)
Allows clients from distant locations to connect, that otherwise wouldn't be able to connect with LAN or WAN
Tunnelling (VPN technology)
Allows the network to send data via other network's connections as if connected to LAN
IPSec (VPN technology)
Protocols to encrypt and authenticate traffic to ensure secure transfer over virtual tunnel
Open Systems Interconnection (OSI) model
Model that defines layers of network interaction
Physical layer (OSI model)
e.g. cabling system components
Data link layer (OSI model)
e.g. Network Interface Card (NIC)
Network layer (OSI model)
Routing
Transport layer (OSI model)
Transmission- error detection
Session layer (OSI model)
Retransmission of data if not received by device
Presentation layer (OSI model)
Encryption and decryption of message for security
Application layer (OSI model)
The end-receiver application, e.g. e-mail
Data packet
Unit of data for transmission with a format, it is part of a message made into a single package
Packet switching
Network communication method: routers direct data packets transmitted along different paths through networks
Protocol
Sets of rules to facilitate a process being carried out correctly
Standard protocol
A protocol recognised as the standard for a certain type of transfer
HTTPS
Creates secure transmission of data from client to server
SSL/TLS
Encryption protocols used on the internet
IPSec (Protocol)
Encrypt and authenticate traffic to ensure secure transfer over VPN tunnel
DHCP
Allows server to automatically assign IP address to client device
Data integrity (Necessity of protocols)
Ensures data is not changed or corrupted during transmission
Flow control (Necessity of protocols)
Controlling flow/load of resources due to limited bandwidth
Deadlock prevention (Necessity of protocols)
Prevents situation where two or more competing programs or actions are sharing a resource
Congestion management (Necessity of protocols)
Prevents requests on network resources exceeding capacity
Bandwidth
Amount of data that can be transmitted over a certain period of time, i.e. theoretical rate of data transfer or speed
Throughput
Actual transfer rate of data
Bottleneck
Created where there are slower segments in a network due to different factors
Data compression
Encoding data using fewer bits than the original to take up less bandwidth and reduce transmission time
Lossy compression
Permanently deletes certain information, only part of the original data is displayed when decompressed
Lossless compression
Eliminates statistical redundancy, all original data can be seen when decompressed
Wireless (Transmission media)
e.g. microwave/ radio signals, satellites, infrared. Least reliable and slowest but cheapest
Metal conductor (Transmission media)
e.g. copper cable, UTP cable, Coaxial cable. Faster, more reliable and expensive than wireless but less than fibre optic
Fibre optics (Transmission media)
Fine optical fibres carrying beams of light as signals. Fastest and most secure but also most expensive
Wireless networking
Wireless devices communicate with no cables, e.g. with radio signals
Modem
Allows you to connect to internet
Wireless repeater
Receives signal from router or access point and rebroadcasts it
1G/2G
First/ second generation of mobile networking and telecommunications technology. Used analogue transmission
3G/4G
Third/fourth generation. Digital, faster than 1G/2G
WiMAX
Worldwide Interoperability for Microwave Access. Serves long-range networking, even in remote areas
Encryption (Network security)
Altering a message into form not understandable to unauthorised person. Only person with the correct key can decode the message
Symmetric-key encryption
Device has a key to encrypt packets, the receiving device has the same key to decrypt
Public-key encryption
Has a public key for encryption and a private one for decryption, both mathematically linked
MAC addresses
Medium Access Control. Every device in a network has a unique MAC address of 12 characters
Firewall (Network security)
Either software installed on each device, or router hardware firewall that protects from hackers accessing devices through wireless connection
Symmetric-key encryption (Evaluating security)
Faster than public-key, Uses less computer resources
Public-key encryption (Evaluating security)
Two sides don't need to share secret key beforehand to communicate
MAC addresses (Evaluating security)
Extra security, Difficult to manage the list as it grows
Firewall (Evaluating security)
Software firewall monitors traffic between device and network and prevents unauthorised access
Sequential/ linear search
Usual search, go through every value and compare to the target value. Simple to implement, data doesn't need to be in order
Binary search
Values in order. Compare search value with middle value. If smaller, compare to middle value of sub-array to the left.
Bubble sort
Compare adjacent values. If not in order, swap round. Simple to write, less code
Selection sort
Splits array into sub-arrays. First sub-array is sorted, second is unsorted. Find the smallest value, place it in the correct position
Loops
Allows a block of code to be executed repeatedly
Suitability of an algorithm
Considerations such as Efficiency, Correctness, Reliability, Flexibility
Big O notation
Measure of efficiency of an algorithm, describing its performance as input size grows
Machine language
Low-level language directly understood by computer, made up of binary numbers.
Assembly language
Low-level language using symbols for instructions and memory addresses.
High-level programming language
Uses elements of natural language. Easy to use for humans and more understandable.
Compiler
Executes translation process only once, translates the whole program. Object program is saved so it doesn't need to be compiled again.
Interpreter
Reads, translates and executes program line by line. Errors are displayed after each line is interpreted.
Source code
Original code/program developed using high level language. Needs to be translated into machine code to be run/executed by the computer.
Variable
Used to store a data element that can be changed during program execution. Has an identifier and type.
Constant
Elements and quantities that don't change. e.g. final double PI = 3.14.
Code reuse
Code reuse across multiple programs.