APCSP - Unit 2 - Digital Information

decimal number system

a base 10 number systen that uses 10 different characters to represent values; each place value is the number 10 raised to a certain power

binary number system

a base 2 number system that uses 2 different characters to represent values; each place value is the number 2 raised to a certain power

bit

a single 0 or 1 in a binary number; short for binary digit

nibble

a group of four bits

byte

a group of eight bits

kilobyte

a group of one thousand bytes or eight thousand bits

megabyte

a group of one million bytes or eight million bits

gigabyte

a group of one billion bytes or eight billion bits

terabyte

a group of one trillion bytes or eight trillion bits

overflow error

a programming error that occurs when attempting to represent a number that is too large

underflow error

a programming error that occurs when attempting to represent a number that is too small

round-off error

a programming error that results from attempting to represent a number that is too precise in binary

ASCII

American Standard Code for Information Interchange

American Standard Code for Information Interchange

a 7-bit encoding scheme for commonly used English letters, numbers, and symbols

Unicode

an international encoding scheme that represents more than 65,000 characters from numerous languages, numbers, symbols, and emoji

analog

continuous streams or waves of data, such as light waves, sound waves; real, tangible things

digital

sampled, non-continuous data

sampling

a process for creating a digital representation of analog data by measuring the analog data at regular intervals (called samples)

pixel

a tiny element of a screen that can produce a color; short for picture element

RGB triplet

three values that affect the brightness of the red, green, and blue portions of a pixel; usually represented in decimal, binary, or hexadecimal

full color

colors represented with 24 bits, allowing for more than 16 million different colors

data compression

a reduction in the number of bits needed to represent data

lossless compression

a reversible process that reduces the number of bits in a digital file without losing any data

lossy compression

a non-reversible process that reduces the number of bits in a digital file by discarding some of the data and informa