Digital Information & Number Systems Flashcards

Flashcards for Digital Information and Number Systems

Digital Information

Computers operate using numbers and translate human-relevant data into numerical form.

Encoding

Turning meaningful data into numerical form so computers can work with it.

Binary Numbers

A number system that uses only 0s and 1s, the lowest level data storage for computers.

Data Abstraction

Simplifying complex data into manageable levels or layers.

Advantages of Digital Representation

Manipulating, analyzing, storing, and sending data.

Number System

A system specifying allowed digits and the meaning of each position in a number.

Decimal Number System

A number system with 10 digits (0-9).

Binary Number System

A number system with 2 digits (0 and 1).

Converting Binary to Decimal

Multiplying each digit by its place value and adding them up.

Bit

A binary digit, either 0 or 1, the fundamental unit of data in computers.

Importance of Simplicity in Hardware

Making things as simple as possible when storing and reading data.

Byte

8 bits, encoding a single character.

Binary Encoding

A mapping from binary sequences to actual data.

ASCII

American Standard Code for Information Interchange. A standard mapping between binary values and characters.

Pixel

The smallest unit of a digital image.

Hexadecimal Number System

A number system with 16 digits (0-9 and A-F).

RGB

Red, Green, Blue. Mixing these three lights at different intensities makes any color.

Data Compression

The process of encoding information using fewer bits than the original representation.

Saving Storage Space

Helps reduce the data footprint.

Speeding Up Transmission

Sending compressed data is faster because there are fewer bits to transmit.

Tradeoff: Storage vs Computation

Compression uses more computational power, which is cheap and fast. In return, we use less storage, which is expensive and slow.

Run Length Encoding (RLE)

Text compression good for text with many repeats.

Lossless Compression

No data is lost.

File Extensions and Compression

File extensions tell the computer which compression algorithm to use for decompression.

Lossy compression

Algorithms reduce file size by permanently removing some data.

Encryption

Scrambling readable data into an unreadable form using a key.

Decryption

Converting scrambled data back to its original form using the same or corresponding key.

Key

A unique random string (e.g., numbers and characters) required to encrypt/decrypt data.

Caesar Cipher (Ancient Example)

Encrypts alphabetic text by shifting letters by a fixed amount (the "key").

Symmetric Encryption

Same key is used for encryption and decryption.

Asymmetric Encryption (Public-Key Encryption)

Uses two keys: Public key (anyone can have it; used for encrypting) & Private key (kept secret; used for decrypting).