CS50 Week 0 Practice Flashcards

A comprehensive set of vocabulary flashcards covering the fundamental concepts of computer science, binary representation, and programming logic introduced in CS50 Week 0.

Computer Science

The study of information, how it is represented and processed, and the application of computational thinking to solve real-world problems.

Computational Thinking

The application of ideas from computer science or CS to solve problems generally in the real world.

Unary Notation

A base-1 system of counting that uses single digits, similar to counting on one's fingers.

Binary

A base-2 system used by computers consisting of only zeros and ones ($0$s and $1$s). Each digit position represents a power of $2$ ($2^0$, $2^1$, $2^2$, etc.).

Bit

Short for binary digit, it is the smallest unit of information in a computer, representing a single $0$ or $1$.

Byte

A unit of digital information measuring $8$ bits.

Transistor

A tiny physical switch inside a computer that represents a bit by allowing electricity to flow ($1$) or not ($0$).

ASCII

Standing for American Standard Code for Information Interchange, it is a standard mapping of integers to English characters; for example, capital A is represented by the number $65$.

Unicode

A superset of ASCII that uses more bits ($16$, $24$, or $32$ bits per character) to represent all human languages, symbols, and emoji.

RGB

A color system using combinations of Red, Green, and Blue, where each color is typically represented by one byte of data ($0$ to $255$).

Pixel

Individual dots or squares that collectively compose a digital image, each assigned a specific color using bits.

Algorithm

Step-by-step instructions for solving a problem correctly and efficiently.

Linear Search

A simple algorithm that checks every item in a list one by one. Its efficiency is represented as $n$.

Binary Search

An efficient algorithm for searching sorted data by repeatedly dividing the search area in half. Its efficiency is represented as $\text{log}_2 n$.

Pseudocode

A human-like, informal representation of a program's logic written in terse English rather than a formal programming language.

Function

Actions or verbs in a program that perform a specific task, such as the purple "say" block in Scratch.

Boolean Expression

A question that results in a binary state, such as true or false, yes or no, or $1$ or $0$.

Conditional

Programming constructs that allow for decision-making or "forks in the road" depending on whether a condition is met.

Loop

A programming construct that induces cyclical behavior, repeating a set of instructions again and again.

Variable

A placeholder in a program that stores a value, such as a number or a name, for later use.

Compiler

A program that translates source code from a higher-level language (like C) into a lower-level language the computer understands (like zeros and ones).

Abstraction

The principle of simplifying complex systems by hiding lower-level implementation details, allowing programmers to build on the work of others.

API

Application Programming Interface; a set of features and functionality provided by one service (like OpenAI) that other programmers can write code against.

Side Effect

An observable action performed by a function, such as displaying a speech bubble on a screen or playing a sound.

Return Value

Information handed back by a function to the program (such as a user's answer) that is not immediately visible to the human user.

Sprite

A character or object in Scratch, such as the cat or a trash can, that can be manipulated through code.