Glossary
ASCII
An older character encoding standard that assigns unique numerical values to letters, numbers, and symbols, allowing text to be represented digitally.
Example:
The letter 'A' is represented by the ASCII value 65, which a computer stores as a specific binary sequence.
Abstraction
The process of simplifying complex systems by hiding unnecessary details and focusing on the essential features.
Example:
When you use a smartphone app, you are benefiting from abstraction because you don't need to know the complex code running behind the scenes.
Analog Data
Data that is continuous and changes smoothly over time, representing real-world phenomena directly.
Example:
The sound waves from your voice are a form of Analog Data before they are converted into a digital recording.
Binary (Base-2)
A number system that uses only two unique digits (0 and 1) and powers of 2 for place values, fundamental to how computers operate.
Example:
A computer represents the number 5 as 101 in Binary (Base-2).
Bit
The smallest unit of data in a computer, represented as either a 0 or a 1.
Example:
Every character you type, like the letter 'A', is ultimately stored as a sequence of bits.
Byte
A unit of digital information that consists of 8 bits, commonly used to represent a single character of text.
Example:
A typical text message might be hundreds or thousands of bytes long, depending on its content.
Data
A collection of facts, figures, or information that can be processed or stored by a computer.
Example:
Your playlist is full of data about songs, like their titles, artists, and genres.
Decimal (Base-10)
A number system that uses ten unique digits (0-9) and powers of 10 for place values.
Example:
When you count to 10, you are using the Decimal (Base-10) system.
Digital Data
Data that is discrete and represented by a finite set of distinct values, typically created by sampling analog data.
Example:
A photograph taken with a digital camera is stored as Digital Data, composed of individual pixels with specific color values.
Hexadecimal (Base-16)
A number system that uses sixteen unique symbols (0-9 and A-F) and powers of 16 for place values, often used as a shorthand for binary.
Example:
Web designers often use Hexadecimal (Base-16) codes like #FF0000 to specify the color red.
Number Base
The number of unique digits, including zero, used to represent numbers in a positional numeral system.
Example:
The number base we use daily is base-10, which has ten unique digits (0-9).
Overflow Error
An error that occurs when a calculation or data storage attempt produces a result that is too large to be stored in the allocated memory space.
Example:
If a game tries to store a player's score that exceeds the maximum number its variable can hold, an overflow error might cause the score to reset to zero or become a negative number.
Rounding Errors
Inaccuracies that occur when a computer represents real numbers with a limited number of bits, leading to slight discrepancies due to truncation or rounding.
Example:
Calculating 1/3 in a computer might result in 0.3333333 instead of a perfectly repeating decimal, illustrating rounding errors.
Sampling
The process of converting analog data into digital data by measuring the analog signal at regular intervals and recording its values.
Example:
When a microphone records your voice, it performs sampling by taking many discrete measurements of the sound wave per second.
Unicode
A modern, comprehensive character encoding standard that assigns unique numerical values to characters from almost all writing systems, supporting a much wider range of symbols than ASCII.
Example:
To display emojis or characters from languages like Chinese, your computer relies on the Unicode standard.