Computing innovations solve problems, express ideas, or provide useful services.
Collaboration helps programmers share ideas, test solutions, and find mistakes.
The development process usually includes:
1. Identify a problem
2. Design a solution
3. Create a prototype
4. Test and revise
5. Share the result
A computing artifact is a product created with computing, such as an app, website,
game, or animation.
Data
Data is information represented in a form computers can store and process.
Computers represent all data using bits.
A bit has one of two values: 0 or 1.
Eight bits equal one byte.
Larger units include:
Kilobyte: about 1,000 bytes
Megabyte: about 1,000 kilobytes
Gigabyte: about 1,000 megabytes
Binary is a base-2 number system using only 0 and 1.
Abstraction hides unnecessary details so people can focus on important information.
Lossless compression preserves all original data.
Lossy compression removes some data to reduce file size.
The Internet
The Internet is a worldwide network of connected devices.
A network is a group of connected computers that communicate.
Data is divided into packets before being sent across a network.
Routers direct packets to their destinations.
Protocols are agreed-upon rules for communication.
Common protocols include:
1. HTTP/HTTPS: web communication
2. DNS: converts domain names into IP addresses
, 3. TCP: helps packets arrive reliably
4. IP: identifies destinations
Bandwidth is the maximum amount of data transmitted over a connection in a given
time.
Latency is the delay before data begins transferring.
Redundancy allows information to travel through alternate paths if one path fails.
Encryption protects data by converting it into a form unauthorized users cannot easily
read.
Cybersecurity
Cybersecurity protects computers, networks, programs, and data.
Common threats include:
1. Phishing
2. Malware
3. Viruses
4. Ransomware
5. Denial-of-service attacks
6. Weak passwords
Authentication verifies a user’s identity.
Authorization determines what an authenticated user is allowed to access.
Strong security practices include:
1. Using unique passwords
2. Enabling multi-factor authentication
3. Installing updates
4. Avoiding suspicious links
5. Backing up important files
A vulnerability is a weakness that can be exploited.
Encryption and access controls help protect private information.
Programming and Algorithms
An algorithm is a finite set of steps used to solve a problem.
A program is an algorithm written in a programming language.
Important programming concepts include:
1. Variables: store values
2. Assignment: gives a value to a variable
3. Expressions: combine values and operators