Review Notes on Digital Information, Number Systems, Data Compression, Cryptography, Internet Hardware, Packets and Protocols, and Cybersecurity.

Flashcards covering key vocabulary and concepts from given lecture notes on digital information, number systems, data compression, cryptography, internet hardware, packets and protocols, and cybersecurity.

Computers Operate on Numbers

The fundamental operation of computers is based on numerical data, particularly binary information of 0s and 1s.

Encoding Information

Various formats of human-readable information—like words, locations, and biological instructions—are encoded numerically for computer processing.

DNA as Data

DNA encodes all genetic instructions in a simple sequence of four characters (A, T, C, G), similarly to how computers encode information.

Data Abstraction

The process of simplifying data into layers of abstraction allows for easier manipulation and understanding of complex information.

Applications of Digital Data

Self-driving cars demonstrate how digital information is utilized for real-time environmental analysis and decision-making.

Programming Examples

Practical programming demonstrations show how numerical data can be encoded and decoded to provide meaning in relatable ways.

Binary System as Foundation

The binary number system (base-2) is crucial because it simplifies computations and data storage, aligning with how transistors work in modern electronics.

Encoding and Decoding Processes

Encoding transforms human-readable data into a numerical system, while decoding reconverts the numerical representation back into a comprehensible format.

Impact of Information Encoding

The necessity of attaching meaning to numbers parallels numerous real-world scenarios and systems, enhancing usability. Common applications range across industries, signifying how integral encoding is for communication, transportation, and social organization.

Data Abstraction Importance

The concept of layering abstraction allows systems (both biological and computational) to focus on specific data levels appropriately without being bogged down by underlying complexities. This hierarchy supports efficient processing and is fundamental to system design.

Vastness of Digital Information

The sheer volume of information available today emphasizes the inadequacy of previous storage methods. Comparing data to physical punch cards illustrates the exponential growth in storage capability afforded by digital technology.

Speed of Digital Communication

The speed at which digital data can be transmitted over distances is remarkably higher than traditional forms of messaging. Concepts like packet transfer demonstrate the efficiency of coding and sending small chunks of data that can be reconstructed anywhere in the world almost instantly.

Real-World Applications and Future Implications

Mastering how computers deal with information through encoding and abstraction is foundational for understanding computer science.

Introduction to Number Systems

a structured approach to represent numbers, utilizing a defined set of symbols and rules. (e.g., decimal, binary, hexadecimal)

Decimal System Mechanics

base-10, ten unique symbols (0 through 9) to represent numbers. The value of each digit in a number is determined by its position

Positional Value Comparison

Harmonizing the workings of decimal and binary systems according to positional value.

Importance of Base

Insight into how different bases affect numerical representation.

Number System

A structured way to represent numbers based on defined rules and digits.

Base

The foundational number from which a system derives its digits (e.g., base 10 for decimal, base 2 for binary).

Positional Value

Each digit's significance determined by its position within a number.

Transitioning between Bases

The method to convert values from one number system to another through positional manipulation.

Binary Representation

How numbers are represented in binary using only the digits 0 and 1.

Conversion Methodology

Emphasis on mathematical principles to convert numbers from one system to another using systematic approaches.

Decimal to Binary Conversion Example

A clear example shows the conversion of the decimal number 13 into its binary equivalent, 1101.

Power Representation in Binary

Explanation of how binary representation breaks down numbers into sums of powers of 2.

Equal Value, Different Expression

The speaker explains that while different bases may utilize distinct digits, they can represent the same quantity in various forms.

Similarity of Number Systems

Conveys that all numbering systems operate on similar mechanics, allowing conversions and expressions to function interchangeably.

Simplicity in Binary Representation

The choice of using only 0s and 1s minimizes complexity in hardware, facilitating easier data storage and retrieval.

Standardization through Protocols

The necessity of universally accepted encoding systems like ASCII (American Standard Code for Information Interchange)

Encoding as a Mapping Process

At its core, encoding is a mapping process where binary sequences are translated into human-readable formats.

Binary Representation

Emphasizes that computers only understand zeros and ones, which encapsulates all forms of data storage.

Understanding Pixels

Pixels are tiny squares that form the basis of digital images, represented as a grid of colors.

Basic Color Encoding

Illustrates a simple encoding system where zero represents black and one represents white, laying the groundwork for black-and-white images.

Bit Interpreter Tool

Uses a visual tool to demonstrate how binary values are interpreted as colors, aiding comprehension of image representation.

Hexadecimal System

The hexadecimal number system, base-16, utilizes 16 symbols (0-9, A-F), critical for programming and digital systems.

RGB Color Encoding

The RGB encoding system allows for the representation of colors using varying intensities of red, green, and blue light. (0-255)

Pixel Manipulation

involves directly altering the color values of individual pixels within a digital image. Techniques include adjusting brightness, contrast, color balance, and applying filters.

Data Compression

Compression shrinks digital information to take up less physical space.

Lossless Compression

The original data can be perfectly reconstructed from the compressed data. Notable algorithms can reduce file size to nearly half without loss of quality.

Run-Length Encoding (RLE)

The algorithm encodes sequences by replacing repeated characters with a single character followed by a count, streamlining storage requirements dramatically.

Lossy Compression

method that reduces file size by removing data, resulting in a smaller compressed file.

Pros:Significantly smaller compressed files compared to lossless compression.Often undetectable loss of quality for images, audio, and video.Cons:The decompressed data is not identical to the original, only an approximation (so not good fr text).Common Algorithms JPEG (images)MP3 (audio)MPEG-4 (video)

Cryptography

The mechanics of sending secret information to keep it confidential.

Encryption

Scrambles digital data into an unreadable form for security.

Key

Data is encrypted using a key: a unique sequence of characters and numbers.

Decryption

What turns encrypted data to its original form.

Public and Private Keys

Each user has a public key for encryption and a private key for decryption.

Definition of Networks

The essence of a network as a group of linked computers and outlines scalability challenges.

Role of Routers

Crucial elements that simplify connections between multiple networks.

Three Data Transmission Methods

The core methods for transmitting data, each with unique characteristics; ethernet facilitates short distance and fiber optics faciliates high-cost, long distance.

Understanding Bandwidth and Latency

Bandwidth refers to the maximum rate of data transfer across a network, typically measured in bits per second (bps). Higher bandwidth allows for more data to be transmitted simultaneously, improving overall network speed and performance.

Latency is the time delay between sending and receiving data, measured in milliseconds (ms). Lower latency ensures quicker response times and smoother real-time applications, such as video conferencing and online gaming.

Both bandwidth and latency are critical factors in evaluating network performance, as high bandwidth with high latency can still result in a poor user experience, and vice versa.

Packets and Protocols in Internet Communication

In internet communication, data is divided into small units called packets, which are then transmitted across the network. Protocols are sets of rules that govern how these packets are sent, received, and interpreted. Key protocols include TCP/IP, which ensures reliable data transmission by breaking data into packets

IP Addresses

Each computer on the internet has a unique identifier, originally using IPv4 format.

Domain Name System (DNS)

Translates human-readable domain names into their corresponding IP addresses.

The Role of TCP and IP in Data Transmission

Ensures that packets are correctly routed across the internet by establishing a framework for communication.

Cyber Crime

Involves crimes using technology, often targeting individuals through identity theft, financial fraud, and unauthorized access to private information.

Cyber Warfare

Conducted at a military level by nations; involves hacking into government systems and critical infrastructure such as communication and energy production.

DDoS Attack (Distributed Denial of Service)

Hackers use numerous compromised computers to overwhelm a web server with requests, causing it to crash and deny service.

DNS Spoofing

A hacker intercepts requests between a user’s computer and DNS resolver, providing false IP addresses that lead users to fraudulent websites designed to steal personal information.

Encryption Protocols

Essential for scrambling data so that only intended recipients can read it; relies on established standards like SSL and TLS. Secure URLs start with 'https' indicating encrypted communication.

Antivirus Software

Crucial in detecting and removing malicious programs that can compromise computer security.