IB Computer Science SL Complete

3G/4G

Standards for wireless mobile connectivity allowing access from mobile devices to the internet.

Abstraction

The process of identifying the properties and behaviours of real things or ideas that need to be represented in code.

Accessibility

The availability of a system to all people, regardless of disability or severity of impairment.

address bus

A parallel bundle of metal traces used to electrically transfer the memory location to be read from/written to.

Aggregation

A relationship between two objects which indicates that one is made up of the other. For example a car has a relationship with it's wheels.

Aggregator

A register of the CPU that stores the output of the ALU

Algorithm

A process or set of rules to be followed in calculations or other problem-solving operations, especially by a computer.

Algorithm

A series of steps designed to solve a mathematical or other problem

Alpha Testing

A group of programmers within the organisation examine early versions to see how the system performs. It is conducted when the software may still be unstable or has incomplete data functionality.

ALU (Arithmetic Logic Unit)

Responsible for computing mathematic and boolean operations. A component of the CPU

Analysis and Design Phase

This is where data models, prototype designs and testing plans are developed.

AND

the output is true when both inputs are true; otherwise the output is false.

Application Layer (OSI)

Performs various services for the application used by the end users

Arguments/Parameters

Objects or primitives passed into a method for use by it's internal algorithms.

Array

A data structure containing a fixed-size list of values/objects of the same type

Assembler

A program to convert assembly-level commands into machine code

Assembly Language

A low-level programming language that uses more memorable mnemonic codes and labels to represent machine-level code. Each instruction corresponds to just one machine operation

Assignment

Setting the value of a variable

Association

A relationship between two objects which may be either a dependency (uses) or aggregation (is made up of).

Automated Testing / Testbenches

Used when there are tests that can't be accomplished by manual testing because they would consume too much time and resources. It is when another software is used to check the performance of the software

automatic updates

when software collects and installs updates from a remote service without user interaction

Beta Testing

A small subset of actual users adopt the new system for feedback purposes. Is conducted when the software is close to being ready for release and few errors are expected.

Binary Search

Start examining values of an array in the center and narrow down your search, halving the search area each time.

Binary

a base 2 numbering scheme in which there are only two possible values for each digit: 0 and 1.

Bit (binary digit)

the smallest unit of data in a computer (0 or 1).

Boolean operator

simple words (AND, OR, NOT, or AND NOT) used as conjunctions to combine or exclude keywords in a search, resulting in more focused and productive results

Boolean

A value that can only be true or false

browser

an application program that provides a way to look at and interact with all the information on the World Wide Web

Bubble Sort

A simple algorithm that repeatedly steps through the list to be sorted, compares each pair of adjacent items and swaps them if they are in the wrong order. The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted

bus topology

Computer network in which all the devices connect together through a common cable

bus

A connection between two or more components of a computer system used for transporting binary information.

Byte

a unit of data that is eight binary digits (bits) long; can represent a letter, number, or typographic symbol.

cache memory

Memory storage built on or very close to the CPU to allow super fast read/write access.

CAD (Computer-Aided Design)

software used by architects, engineers, drafters, artists, and others to create precision drawings or technical illustrations.

Cast

A reference to one object or data type can be changed to a reference to another object or data type by this process. The objects in the class need to be related by inheritance or in the case of primitives have a defined way of changing available.

Change Management

An approach to transitioning individuals, teams, and organisations to a desired future System.

Character

A single letter, number, or symbol

Class

An extensible program-code-template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions or methods).

Client

a computer accessing resources hosted by another computer/the server

client

A computer system or software that requests a service from a server connected to the same network.

Collection

A data structure containing a variable-size list of values/objects of the same type

Comparison

Comparing the values of two items and returning TRUE of FALSE depending on the results

Compatibility Issues

These occur when elements in a System are not designed to work together and require extra elements to translate between them.

Compiler

Translation software that converts high level source code into machine code by analysing whole blocks of source code

Compound Operation

A task that requires a combination of many fundamental operations for a CPU to complete

Congestion Management

A network protocol that allows network infrastructure to restrict transmission rates to and from clients and servers when the total network load is high.

Constant

A label referring to a location in memory containing a value that can be accessed but not changed by a program

Constructor

In OOP a special type of method which has the same name as the class and is used to create objects. This creation process is known as instantiation.

CPU (Central Processing Unit)

Component of a computer responsible for gathering data and instructions, interpreting and executing instructions, and sending data/results to storage.

CU (Control Unit)

Part of the CPU that implements the microprocessor instruction set; it extracts instructions from memory and decodes and executes them, and sends the necessary signals to the ALU to perform the operation needed.

data bus

A parallel bundle of metal traces used to electrically transfer data to and from the CPU and Main Memory.

Data Integrity

A network protocol that determines whether the data received at the destination matches the data sent by the source

data integrity

The accuracy of data after input, transmission, storage or processing

Data Link Layer (OSI)

Error handling of physical transmission, builds frames and amends transmission rate according the buffer of the receiver

Data Migration

The process of importing legacy data to a new system.

Data Security Issues for a New System

Data can be valuable (as an asset) or a liability (if lost).

Data Type

In Java, every variable has a type declared in the source code. There are two kinds of types: reference types and primitive types. Reference types are references to objects.

Data Validation

The process of ensuring that a program operates on clean, correct, and useful data.

database management system

a program that lets one or more computer users create and access data in a database

Deadlock Prevention

A network protocol that prevents compound network errors from leaving both client and server in passive states waiting from a response from each other.

Debugging

identifying and removing errors from computer hardware and software

Declaration

Identifying a variable or constant or array to a program so that memory space can be aollocated

Decomposition

The breaking down of a complex problem into smaller parts that are easier to understand. In the case of OOP systems are broken down into smaller classes or objects.

denary/decimal

the base-10 number system, probably the most commonly used number system. (numbers 0-9)

Dependancy

A relationship between two objects where one requires, but does not instantiate another

Dependency Issues for a New System

Reliance on a single component in a System without backup

Direct Change Over

The old system is stopped completely, and the new system is started. All of the data that used to be input into the old system now goes into the new one.

email

software which allows users to send and recieve electronic messages, attach files and forward on to others.

Embedded Assistance

Many systems will now come with user documentation such as tooltips and dynamic page content within the system itself.

Encapsulation

This is used to refer to one of two related but distinct notions, and sometimes to the combination thereof:
A language mechanism for restricting access to some of the object's components.
A language construct that facilitates the bundling of data with the methods (or other functions) operating on that data.

Ergonomics

The physical relationship between people and the system they interact with.

Error Checking

A network protocol that ensures both sender and receiver agree on protocols for transmission

Evolution and Maintenance Phase

Small changes like patches are applied. Larger changes caused by internal or external factors might redefine the requirements of a system.

Exception

An event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions. When an error occurs within a method, the method creates an object and hands it off to the runtime system.

Existing Literature

Used to compare the system requirements and functionality with other turn-key systems.

Extends

A keyword used to indicate that one class inherits from another.

Extensibility

Something, such as a program, programming language, or protocol, that is designed so that users or developers can expand or add to its capabilities

extranet

An resource (such as a website) within an local network that is open to external entities (e.g. a retailer might allow access to certain systems for its suppliers.)

Feedback Loop

Allows outputs to be fed back into a system as inputs to allow for adjustment of a process.

Final

A Java keyword. It can be applied to a variable, a method or class and indicates that it cannot be changed , derived from over ridden or extended.

Firewall

Allows only authorised network traffic

Flow chart

A diagrammatic method of showing the structure and data flow to define a problem and its solution

Flow Control

A network protocol that allows a destination of data to request transmission rates that match its capabilities to process the data

Flowchart Symbol: Oval

Start or End to an algorithm

Flowchart Symbol: Rectangle

A process to be completed

Flowchart Symbol: Rhombus

A decision

Function

A method that returns a value

Function

A type of method that may performs a task but will always return a value

Fundamental Operation

A task that can be performed natively by a CPU

Getter/Accessor

A method that returns a member variable and helps to maintain it's encapsulation.

graphic processing software

software that allows the creation and manipulation of digital graphics e.g. photograph editing and manipulation

GUI (Graphical User Interface)

A way for users to interact with software by interpreting visual elements like toolbars, buttons, and other controls.

Hardware

All the physical parts that make up a computer, such as the motherboard, CPU, RAM, and power supply.

Help Files

This is a file attached to the program which contains the documentation organised by topic. Its consistent availability is its main advantage.

hexadecimal

a base-16 number system consisting of the symbols 0 through F.

High-level language

A programming language that resembles natural language. Each instruction translates to many machine instructions. It is problem based rather than machine based

Implementation Phase

The process of creating the system. This is the coding phase.

Index

an integer that refers to the position of data in an Array

Inheritance

In this coding construct a class that is derived from another class is called a subclass (also a derived class, extended class, or child class). The class from which the subclass is derived is called a superclass (also a base class or a parent class).
Subclasses gain access to the public and protected members and methods of the superclass directly but not the private members and methods. Hence the Objects of the subclass become hybrids of the super and sub classes.

Initialization

A special kind of assignment: the first, before, objects have null value and primitive types have default values such as 0 or false. Can be done in conjunction with declaration.