← Computer Science Principles syllabus

United StatesComputer Science Principles

Big Idea 4: Computer Systems and Networks

3 dot points across 3 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does redundancy make a network fault tolerant, so it keeps working when parts fail?

Topic 4.2 Fault Tolerance: a system is fault tolerant if it continues to operate when some components fail; redundancy (multiple paths or copies) is the main way networks achieve fault tolerance.
A focused answer to AP CSP Topic 4.2, covering what fault tolerance means, how redundancy of paths and data provides it, why the Internet is fault tolerant, the difference between a fault-tolerant and a non-redundant system, and the costs of redundancy.
9 min answer →

How do parallel and distributed computing speed up work, and what are the limits of the speedup?

Topic 4.3 Parallel and Distributed Computing: parallel computing runs tasks simultaneously on multiple processors and distributed computing spreads work across multiple computers, improving speed but with limits.
A focused answer to AP CSP Topic 4.3, covering sequential versus parallel computing, distributed computing, speedup and its calculation, why some tasks cannot be fully parallelised, the benefits of solving large problems, and worked speedup reasoning.
10 min answer →

How does the Internet move data between devices using addressing, packets and shared protocols?

Topic 4.1 The Internet: the Internet is a network of networks that moves data in packets using protocols such as IP and TCP, with addressing, routing and standards enabling scalable communication.
A focused answer to AP CSP Topic 4.1, covering the Internet as a network of networks, IP addresses, packets and packet switching, protocols (IP, TCP, HTTP, DNS), bandwidth and latency, redundancy in routing, and why open standards enable scalability.
11 min answer →