The Hamilton and Alexandra College · Year 12 · 2026

A glossary of every term you need to recognise and use correctly across C06. Click a term to expand its definition. The C06 pages — and the feedback graded against them — use these words, so learn them in the language the rubric uses.

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>| ### compiler

>| A program that turns source code into machine language that can be executed by a computer processor.

>| ### event

>| A special type of method that is called when an object's state changes.

>| ### flow of execution

>| The order in which instructions, conditions, and iterations are executed or evaluated.

>| ### graphical user interface (GUI)

>| A type of user interface that allows users to interact through visual elements such as windows, icons, and buttons.

>| ### hard-coding

>| To include fixed data in a program that cannot be changed during runtime and can only be changed by modifying the program source code.

>| ### instruction

>| A unit of code that can be executed by a compiler or interpreter.

>| ### interpreter

>| A computer program that directly executes source code without needing to have it compiled beforehand.

>| ### prolog

>| The information in an XML file that appears before the start of the document's contents, including information such as the XML version and character encoding that is being used.

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>| ### arithmetic operator

>| A symbol in programming that performs basic mathematical operations such as addition, subtraction, multiplication, and division.

>| ### conditional operator

>| A symbol used to compare two values within a condition, such as equals (`==`), not equals (`!=`), greater than (`>`), less than (`<`), greater than or equal to (`>=`), or less than or equal to (`<=`). Used inside selection and iteration conditions to decide whether a branch runs or a loop continues. (Not to be confused with the ternary conditional *expression*, e.g. `x if condition else y` in Python — that's shorthand for an if/else selection, not a comparison.)

>| ### logical operator

>| A Boolean operator used to combine expressions, such as AND, OR.

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>| ### alternative execution

>| Code that is run if a condition is not met.

>| ### chained selection

>| A selection structure with more than one condition checked in sequence (e.g. `if` / `elif` / `elif` / `else`), where each branch can test a different condition. Execution stops at the first branch whose condition is true.

>| ### DO/WHILE

>| An iteration over a set of instructions, conditions, and/or iterations that is repeated for as long as a condition is met; it is always run at least once.

>| ### FOR

>| An iteration over a set of instructions that is repeated a predefined number of times.

>| ### infinite loop

>| An iteration that will never reach the condition upon which it can terminate.

>| ### nested selection

>| When a selection contains one or more additional conditions within its structure.

>| ### REPEAT/UNTIL

>| An iteration over a set of instructions that is repeated for as long as a condition is not met; it will always execute at least once.

>| ### selection statement

>| A control structure that allows a programmer to write lines of code that are only run when a particular requirement is met.

>| ### sequence

>| A set of instructions that executes line by line in the order that it is written.

>| ### switch/case

>| A selection structure that compares a single value or expression against a list of specific possible values (cases), running the matching branch's code (e.g. `match`/`case` in Python, `switch`/`case` in TypeScript). Unlike chained selection, every case tests the *same* expression for equality against a different value, rather than evaluating independent conditions per branch.

>| ### WHILE

>| An iteration over a set of instructions that is repeated for as long as a condition is met.

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>| ### casting

>| Converting a variable from one data type to another, such as converting a string to an integer.

>| ### constant

>| A fixed value that, once defined, cannot be altered during the execution of a program.

>| ### global variables

>| Variables that are defined outside any function and can be accessed by all functions throughout the source code.

>| ### local variables

>| Variables that are defined inside a function that can only be accessed by that function.

>| ### variable

>| A method of storing and labelling data to be referenced and manipulated in a computer program.

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>| ### Boolean

>| A data type with one of two possible values, 0 and 1, usually referred to as False and True, respectively.

>| ### character

>| A data type representing any single meaningful unit, such as a letter, a number, a punctuation mark, a symbol or even a space.

>| ### data type

>| A method of classifying a variable to determine the data that variable can contain, as well as how that variable can be manipulated.

>| ### floating point

>| Computer representation of real numbers, with decimal places.

>| ### integer

>| A data type representing whole positive and negative numbers.

>| ### numeric

>| A data type consisting of whole numbers, referred to as integers, and decimal numbers, referred to as floating points.

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>| ### array

>| A list of elements indexed by position. In most programming languages, the first element has index zero.

>| ### data structure

>| A method of organising data to allow particular operations to be performed on it efficiently.

>| ### dimension

>| The direction or the level of organisation within a data structure, such as an array.

>| ### field

>| A single data item in a record (e.g. FamilyName).

>| ### record

>| A complete set of fields relating to an entity, such as a person.

>| ### tree

>| The structure of an XML file that contains a root element and all of its sub-elements.

>| ### two-dimensional array

>| A data structure that stores elements in a grid-like format, organised into rows and columns, allowing access using two indices.

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>| ### child element

>| Any sub-element of a parent element in an XML file.

>| ### CSV

>| A comma-separated value file, which is a delimited file separated by commas.

>| ### delimiter

>| The character used to separate data values in a delimited file.

>| ### parent element

>| Any element in an XML file that contains at least one sub-element.

>| ### plain text (TXT) file

>| A structured file that contains characters of readable data.

>| ### root element

>| A parent element to all other elements in an XML file.

>| ### text file

>| A structured file containing sequences of characters that are not encrypted, such as a plain text file or CSV file.

>| ### XML

>| Extensible Markup Language; a metalanguage that allows for user-defined tags and rules for encoding documents in a format that is readable by humans and machines.

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>| ### arguments

>| Specific inputs passed into a function that act as local, temporary variables.

>| ### function

>| A sequence of related code that has been given a name that can be called from other points in the source code.

>| ### function call

>| To execute the contents of a function.

>| ### function declaration

>| To name a function and its arguments.

>| ### function definition

>| To define (write) the contents of a function.

>| ### method

>| An action an object can carry out (e.g., window.refresh, golfClub.swing).

>| ### parameters

>| See arguments.

>| ### pass by reference

>| To pass data into a function as an argument so that it can be modified without needing to be returned.

>| ### pass by value

>| To pass data into a function as an argument so that it cannot be modified without needing to be returned.

>| ### return value

>| A value or set of values that is passed back to the origin of a calling function, often to be assigned to a variable, used in an equation, or tested within a conditional statement.

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>| ### abstraction

>| An object-oriented programming language principle that allows programmers to manage complexity by hiding implementation details and exposing only the essential features of an object.

>| ### class

>| A program code template for creating objects in object-oriented programming languages.

>| ### encapsulation

>| An object-oriented programming principle that involves bundling the data and methods that operate on the data into a single unit or class.

>| ### generalization

>| The process of defining a general class (superclass) that encapsulates common attributes and behaviors of more specific classes (subclasses).

>| ### inheritance

>| A method of basing an object or class on another object or class, taking on its attributes and methods and potentially extending upon them.

>| ### instantiation

>| In object-oriented programming, the process by which an object is created from a class.

>| ### object

>| Any instantiated class that a program can inspect and/or change, in terms of appearance, behavior, or data.

>| ### object-oriented programming (OOP)

>| A programming language based on the concept of objects that contain data in the form of fields or attributes and code in the form of methods.

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