WGU D684 Intro to CS Key Terms Only

data

Raw facts and figures that can be processed to produce meaningful information.

information

Data that have been processed or organized in a meaningful way to be useful.

analog data

Data represented in a continuous and variable form.

digital data

Data represented using discrete binary values (zeroes and ones).

binary

A numerical system that uses only two digits, zero and one, to represent data in computing.

integer

A whole number.

real

A data type representing numbers that can have fractional parts, often called floating-point numbers.

floating point

A way to represent real numbers that can have fractional parts using a format that includes a base and an exponent.

numeric

Any value that is a number.

string

A sequence of characters treated as a single data element and used for text manipulation.

data types

Categories of data that define what kind of value can be stored, like integers, floats, and strings, and how it can be used.

radix point

The decimal point in a number system that indicates the separation between integer and fractional parts.

scientific notation

A method of representing very large or very small numbers by using powers of 10.

signed-magnitude representation

A way of encoding positive and negative numbers where one bit represents the sign and the remaining bits represent the magnitude.

ten's complement

A mathematical method for representing negative numbers in a decimal system.

character

A single letter, digit, or symbol used in writing text.

character set

A collection of characters that a computer can recognize and process, like ASCII or Unicode.

American Standard Code for Information Interchange (ASCII)

A standard encoding system for text characters that uses numeric values to represent letters, numbers, and symbols.

Unicode

A universal character set that includes characters from virtually all writing systems, allowing for consistent encoding and representation of text globally.

data compression

The process of reducing the size of data to save space or transmission time.

compression ratio

The ratio of the original data size to the compressed data size, indicating how much the data has been reduced.

lossless

A type of data compression where no information is lost and the original data can be perfectly reconstructed.

lossy

A type of data compression that reduces file size by permanently eliminating some information, which may affect quality.

Huffman encoding

A compression technique that uses variable-length codes for data representation based on frequency of occurrence.

keyword encoding

A method of data compression that replaces frequently occurring patterns with shorter codes.

run-length encoding

A simple compression technique that replaces sequences of repeated characters with a single character and a count.

control structure

Constructs in programming that control the flow of execution, such as loops and conditional statements.

declaration

A statement in programming that specifies the name and type of a variable or function without assigning a value.

Boolean expression

A logical statement that can only be true or false and uses operators like AND, OR, and NOT.

strong typing

A feature in programming languages where each variable is explicitly declared to be of a specific type, reducing errors.

bandwidth

The maximum rate of data transfer across a network or communication channel, usually measured in bits per second.

overflow

A condition in which a calculation exceeds the maximum value that can be represented within a given number of bits.

pulse-code modulation (PCM)

A method used to digitally represent analog signals.

reclocking

The process of refreshing the timing signals in digital data to ensure accuracy and synchronization.

camel casing

A naming convention where the first letter is lowercase and each subsequent word starts with an uppercase letter, like myVariableName.

Hungarian notation

A naming convention where the name of a variable starts with a prefix indicating its type, like strName for a string variable.

kebob case

A naming convention where words are all lowercase and separated by hyphens, like my-variable-name.

mixed case with underscores

A naming convention that combines uppercase and lowercase letters with underscores between words, like MyVariableName.

Pascal casing

A naming convention in which each word in the name starts with an uppercase letter, like MyVariableName.

snake casing

A naming convention in which words are all lowercase and separated by underscores, like myvariablename.

alphanumeric values

Characters that include both letters (A-Z) and numbers (0-9).

identifier

A name given to a variable, function, or other item in code to identify it.

initializing a variable

Assigning an initial value to a variable when it is declared, like int x = 10.

numeric constant

A fixed number value written directly in the code, like 42.

numeric variable

A variable that holds a number value.

string constant

A fixed sequence of characters written directly in the code, like 'Hello, World!'.

string variable

A variable that holds a sequence of characters (a string).

unnamed constant

A fixed value used directly in code without assigning it to a variable, also known as a magic number, like 3.14 for π.

variable

A named storage location in memory that can hold different values throughout a program.

assignment operator

A symbol used to assign a value to a variable, typically =.

assignment statement

A line of code that assigns a value to a variable, like x = 5.

binary operator

An operator that takes two operands, such as +, -, *, and /.

keyword (reserved word)

A reserved word in a programming language that has a specific meaning and cannot be used as an identifier, like if, while, and class.

lvalue

An expression that refers to a memory location, which can appear on the left side of an assignment, like x in x = 5.

operand

A value or variable on which an operator acts, like 3 and 5 in 3 + 5.

right-to-left associativity

The order in which operations are performed in expressions where operators of the same precedence appear, processed from right to left.

garbage

Unused or leftover data in memory that the program no longer needs or references.

type safety

Ensuring a variable is only used in ways consistent with its data type, preventing type errors.

abstract step

A high-level action in an algorithm that describes what needs to be done without detailing how to do it.

algorithm

A step-by-step set of instructions designed to perform a specific task or solve a problem.

pseudocode

A simplified, human-readable version of a program's code that outlines the logic without strict syntax rules.

branch

A point in an algorithm where a decision is made, leading to different actions based on conditions (e.g., if-then statements).

nested structure

A programming construct where one control structure (like a loop or a conditional statement) is placed inside another.

selection

A control structure that allows a program to choose between different actions based on conditions (similar to a branch).

infinite loop

A loop that never ends because the termination condition is never met or is incorrectly written.

loop control variable

A variable that determines whether the loop will continue running or stop, often incremented or modified within the loop.

pretest loop

A loop that evaluates its condition before executing the body of the loop, such as a while loop.

repetition (iteration)

The act of executing a set of instructions multiple times, typically using loops.

input

Data that is provided to a program for processing.

output

Data that is produced by a program and presented to the user or another system.

left-to-right associativity

The rule that operators with the same precedence are evaluated from left to right in an expression.

rules of precedence (order of operations)

The rules that define the sequence in which different operations (like addition and multiplication) are performed in an expression to ensure consistent results.

magic number

A hard-coded number in a program that lacks context or explanation, making the code harder to understand and maintain.

named constant

A variable with a value that is set once and cannot be changed; it is used to give meaningful names to fixed values.

overhead

The extra processing time, memory, or other resources required by a computer program beyond the actual task it is performing.

abstract data type

A blueprint for organizing and working with data that defines what operations can be performed on the data without specifying how they are implemented.

data structure

A way of organizing and storing data in a computer's memory designed to facilitate the efficient retrieval, insertion, and deletion of data.

composite variable

A variable that can hold multiple pieces of data, often grouped together under a single name.

record

A data structure that groups related pieces of information under a single name, typically consisting of multiple fields or attributes.

array

A collection of items stored in a contiguous memory block, each identified by an index number, allowing for efficient access to elements based on their position.

list

A collection of items arranged in a linear sequence, allowing for easy access to and the insertion and deletion of elements.

queue

A data structure that follows a first-in, first-out (FIFO) order where elements are added to the back and removed from the front.

stack

A data structure that follows a last-in, first-out (LIFO) order where elements are added and removed from the same end, known as the top.

container

A data structure that holds a collection of elements, providing methods to add, remove, and access items within it.

linked list

A sequence of elements where each element points to the next one, forming a chain.

linked structure

Any structure composed of elements connected by links or pointers, enabling dynamic relationships among data elements.

subprogram (function)

A reusable block of code that performs a task.

argument

The actual value you pass to a function.

parameter

The variable that receives the value in the function.

parameter list

The set of parameters in a function.

reference parameter

Lets the function modify the original variable (Java: arrays/objects).

value parameter

A copy of the value is passed; original is unchanged.

asynchronous

A type of operation that runs independently of the main program flow, allowing additional tasks to happen without waiting for others to complete.

bytecode

A low-level, platform-independent code that is executed by a virtual machine, typically produced by compiling source code.

case sensitive

When a programming language treats uppercase and lowercase letters as different characters.

compiler

A tool that translates source code written in a high-level programming language into machine code or bytecode that a computer can execute.

interpreter

A tool that executes source code directly and translates it into machine code in real time rather than compiling it before.

paradigm

A style or approach to programming—such as object-oriented, procedural, or functional programming—that dictates how code is structured and organized.

strong typing

A feature in which each variable has a specific type and you must follow strict rules about how types are used and combined, helping prevent errors in your code.

class

A blueprint for creating objects in object-oriented programming that defines the properties and behaviors the objects will have.