Computing Systems and the Internet — AP Computer Science Principles
1. Computer System Hardware ★★☆☆☆ ⏱ 4 min
All modern computing devices follow the von Neumann architecture, which splits hardware into four core functional categories with defined roles for processing digital data.
- **Input devices**: Convert real-world analog data (sound, light, movement) to binary digital data. Common examples: keyboards, touchscreens, cameras, microphones, sensors.
- **Processing unit (CPU)**: The "brain" of the device that executes program instructions. It includes the Arithmetic Logic Unit (ALU) for math/logic operations and the Control Unit (CU) that manages data flow between components.
- **Storage**: Split into two types: Primary storage (RAM) is volatile (loses data when power off) high-speed temporary storage for active programs. Secondary storage (SSD, HDD, flash drives) is non-volatile (retains data when off) long-term storage for files and software.
- **Output devices**: Convert binary digital data to human-readable formats. Common examples: screens, speakers, printers, haptic motors.
Exam tip: Examiners frequently test component-function matching, especially distinguishing RAM from secondary storage, which is a common 1-point easy multiple-choice question.
2. The Internet: Packets and Protocols ★★★☆☆ ⏱ 5 min
The internet is a global, decentralized network of interconnected computing devices with no single governing body. Its core design prioritizes fault tolerance: if one network path fails, data can be routed through alternative paths to reach its destination.
- **Internet Protocol (IP)**: Assigns a unique numeric address to every connected device, and routes packets across networks.
- **Transmission Control Protocol (TCP)**: Reliable, connection-oriented protocol that checks for lost/corrupted packets, requests retransmissions, and reassembles packets in order. Used for accuracy-critical use cases: email, file transfers, web browsing.
- **User Datagram Protocol (UDP)**: Fast, connectionless protocol that does not check for or retransmit lost packets. Used for speed-critical use cases: live video streaming, online gaming, video calls.
- **Domain Name System (DNS)**: Translates human-readable domain names (e.g. `collegeboard.org`) to numeric IP addresses that devices use to locate servers.
- **HTTPS**: Encrypted version of HTTP that uses TLS/SSL encryption to protect data transmitted between browsers and web servers.
3. Common Cybersecurity Threats ★★☆☆☆ ⏱ 3 min
Cybersecurity is the practice of protecting systems, networks, and data from unauthorized access, damage, or theft. The AP CSP exam commonly tests identification of threats from real-world scenarios.
- **Phishing**: A social engineering attack that uses fraudulent emails, texts, or fake websites pretending to be from a trusted source to trick users into sharing sensitive data like passwords or credit card numbers.
- **Malware**: Malicious software designed to damage or gain unauthorized access to a device. Common types: viruses (attach to legitimate programs), ransomware (encrypts data and demands payment to unlock), spyware (secretly collects user data).
- **DDoS (Distributed Denial of Service) Attack**: An attacker uses a botnet (network of infected devices) to send millions of fake requests to a target server, overwhelming it so legitimate users cannot access the service.
- **Data Breach**: An incident where an unauthorized user gains access to confidential user data stored by an organization, often leading to identity theft or financial harm.
Exam tip: You will almost always be asked to identify a threat type from a real-world scenario. Memorize the defining feature of each threat to earn these easy marks.
4. Impacts of Computing Innovations ★★★☆☆ ⏱ 4 min
All computing innovations have both beneficial and harmful real-world impacts. The AP CSP exam regularly asks for balanced evaluations of a given innovation, including on the written Create performance task.
#### Beneficial Impacts
- Equitable access to resources: The internet makes education, healthcare, government services, and employment accessible to people in remote/low-income communities.
- Accessibility: Features like screen readers, voice control, and closed captions make content accessible to people with disabilities.
- Scientific progress: High-performance computing powers climate modeling, drug development, genome sequencing, and space exploration.
- Global connection: Low-cost instant communication enables cross-border connection, remote work, and global collaboration.
#### Harmful Impacts
- Digital Divide: Unequal access to high-speed internet and devices creates gaps in educational and economic opportunity for low-income, rural, and marginalized groups.
- Privacy risks: Companies collect large volumes of user data (browsing history, location, habits) often without explicit consent, which can be misused for advertising or surveillance.
- Misinformation: False content spreads rapidly online, leading to public health harms, election interference, and social polarization.
- Environmental harm: Data centers consume large amounts of electricity contributing to emissions, and e-waste contains toxic materials that contaminate the environment.
Common Pitfalls
Why: Students confuse the definitions of short-term and long-term storage
Why: Students assume large global networks must have centralized control
Why: Students associate 'reliable' with better for all applications
Why: Students forget that evaluation questions require balanced analysis
Why: Students rely on common non-technical definitions of cyber threats