AP Computer Science Principles Unit 1: Digital Information Flashcards

A set of 50 vocabulary flashcards covering key topics in digital information representation, binary arithmetic, data compression, sampling, abstraction layers, and intellectual property based on Unit 1 lecture notes and assessment questions.

Bit

A contraction of 'Binary Digit', representing the smallest, most foundational unit of information in a computer as a $0$ or $1$.

Byte

A group of $8$ bits used to store and process data in digital systems.

Abstraction

A simplified representation of something complex that hides low-level details by stacking layers of information.

Why Computers Use Binary

It is cheaper, easier, and much more reliable to build physical hardware components (like transistors) that only need to separate two distinct states (On/Off, High Voltage/Low Voltage).

Decimal System (Base-10)

A number system that uses $10$ digits ($0$ through $9$).

Binary System (Base-2)

A number system that uses $2$ digits ($0$ and $1$), where each place value represents a power of $2$.

Overflow Error

An error that occurs when a computer attempts to handle or calculate a number that is too large to be represented by the fixed number of allocated bits.

Round-off Error

An error that occurs when a computer attempts to represent a number that is too precise (like a repeating fraction), requiring it to truncate or round the value to fit its fixed bits.

ASCII

American Standard Code for Information Interchange; a universally recognized protocol converting numbers into raw text characters.

Digital Color (RGB)

A color model where image pixels are rendered using intensity values of Red, Green, and Blue.

Analog Data

Information that changes smoothly and continuously over time, such as sound waves, a standard thermometer, or a vinyl record.

Digital Data

Information broken down into discrete, finite values, typically represented as $1$s and $0$s.

Sampling

The process of converting analog data into digital data by measuring the analog signal at regular intervals and converting those measurements into numbers.

Lossless Compression

A data compression method that reduces file size without losing any original data, making the process fully reversible.

Lossy Compression

A data compression method that greatly reduces file size by permanently discarding less important data, making the process irreversible.

Intellectual Property

Legal rights that protect digital creations and original works.

Creative Commons

A specific type of public copyright license that lets creators clearly tell the public how they are allowed to share, remix, or reuse their copyrighted work.

Bit Reduction in Compression

Lossy compression algorithms are typically better than lossless compression algorithms at reducing the number of bits needed to represent a piece of data.

Reversibility of Lossless Compression

A property of lossless compression that guarantees perfect reconstruction of the original data upon decompression.

Appropriate Use of Lossy Compression

Ideal for applications needing quick transmission of media files (such as low-quality photos) where smaller data sizes are prioritized over exact detail.

Copyright Ownership of Unlicensed Work

The original creator retains ownership of a work if they did not license it, even if another person copies it and posts it online under a Creative Commons license.

Online Content Citation and Legal Consequences

Using images posted online by another student without permission or citation is an illegal practice most likely to lead to legal consequences.

Open Source Software Modification

The act of altering software distributed under an open source model, which is permissible and unlikely to lead to legal consequences.

Open Access Research

Research publications and materials made freely available for public use without requiring users to acquire individual licenses.

Effect of Image Compression on Bit Count

Compressing an image file decreases the total number of bits required to represent that image.

Computing Devices Representation of Data

The standard method by which computing devices represent all data using bits, where each bit is either a $0$ or a $1$.

Abstractions in Computing

Common higher-level data types represented by computing devices, including numbers, characters, and color.

Role of Abstraction in Managing Complexity

Abstraction helps represent complex information by hiding low-level implementation details rather than exposing them.

Context-Dependent Sequences of Bits

The concept that the exact same sequence of binary bits may represent different types of information depending entirely on the context.

Fixed Bit Limits on Number Representation

Because computers allocate a fixed number of bits for numbers, values that exceed the maximum representable limit cause overflow errors.

Digital Representation of Analog Realities

A smartphone photo of a physical museum painting is a digital representation of an analog object.

4-Bit Binary Overflow Threshold

In a 4-bit binary system representing non-negative decimal numbers ($0$ to $15$), the smallest number for which an overflow error occurs is $16$.

Binary 1001 to Decimal Conversion

The binary value $1001_2$ converts to the decimal value $9$.

Decimal 20 to Binary Conversion

The decimal value $20$ converts to the 5-bit binary value $10100_2$.

Comparison of Binary Values

Comparing 8-bit numbers shows that $11000000_2$ ($192$ in decimal) is larger than $01111111_2$, $00000001_2$, and $10111111_2$.

Total Numbers in an 8-Bit Binary System

An 8-bit binary system can represent a total of $2^8 = 256$ distinct numbers.

Range of Values in an 8-Bit Binary System

An 8-bit binary system representing non-negative integers covers decimal values ranging from $0$ to $255$.

.zip File Format

A common file format used as an example of lossless compression for text and files.

.jpg File Format

A common image file format used as an example of lossy compression.

.mp3 File Format

A common audio file format used as an example of lossy compression.

.mp4 File Format

A common video file format used as an example of lossy compression.

Hardware States in Binary Hardware

The physical states used by computer hardware (such as transistors) to represent binary values: On/Off or High Voltage/Low Voltage.

Binary Place Values (8-Bit)

The positional values in an 8-bit binary number corresponding to powers of 2: $128, 64, 32, 16, 8, 4, 2, 1$.

Digital Information Abstraction Stack

The multi-layered structure of digital information: Light/Electricity \rightarrow Bits \rightarrow Numbers \rightarrow Text \rightarrow Images.

Pixel

An individual dot or picture element in a digital image, rendered using RGB color values.

Sound Waves as Analog Information

An example of analog data characterized by smooth and continuous changes over time.

Vinyl Record

An example of an analog media storage format that records continuous sound signals.

Standard Thermometer

An example of an analog measuring device that displays temperature as a continuous physical measurement.

Truncation in Binary Numbers

The act of cutting off digits in a fractional or precise number to fit a fixed bit allocation, resulting in round-off errors.

Public Copyright License

A standardized legal framework, such as Creative Commons, allowing content creators to grant public permissions to share and reuse their work.