AP Computer Science Principles Unit 2: The Internet

Flashcards covering key computer science principles, vocabulary, network protocols, routing, packets, internet layers, and social dilemmas from Unit 2.

What is the Internet?

A network of interconnected networks that allows computers and other devices to communicate.

What is the key difference between the Internet and the World Wide Web?

The Internet is the underlying network, while the World Wide Web is one service that runs on the Internet.

What is a network?

A group of connected computing devices that can communicate with each other.

What is a protocol in computer networking?

An agreed-upon set of rules that determines how devices communicate.

Why are open standards for Internet protocols important?

Open standards allow devices and software created by different companies to work together and communicate using shared rules.

What is an IP address?

A number assigned to a device on a network that helps identify where data is coming from and where it is going.

What is the primary function of a router?

A router examines information about a packet and determines where to send it next to move data between different networks.

What is routing, and why is Internet routing described as dynamic?

Routing is the process of determining how data travels from its source to its destination. It is dynamic because the path a packet takes is not permanently predetermined, allowing packets to travel along different paths if a connection fails.

What is redundancy on the Internet?

Having multiple possible paths or resources available between devices so that data can take alternative routes.

What is fault tolerance?

The ability of a system to continue functioning when part of the system fails.

How does redundancy contribute to fault tolerance?

Redundancy provides multiple possible paths so that if one connection or router fails, another path can still be used to prevent the entire Internet from failing.

What is a packet?

A small piece of data into which larger amounts of information are divided before being sent across a network.

Why can packets from the same message arrive out of order?

Because packets can travel along different routes across interconnected networks and arrive at different times.

What is TCP, and what are its primary characteristics?

TCP (Transmission Control Protocol) is designed for reliable delivery; it keeps packets organized, detects and retransmits missing packets, but has more overhead.

What is UDP, and what are its primary characteristics?

UDP (User Datagram Protocol) is designed for speed and low overhead, but provides no guarantee of delivery, packet ordering, or retransmission.

What does DNS stand for, and what is its function?

DNS stands for Domain Name System, and it translates human-friendly domain names into IP addresses.

What does HTTP stand for, and what is it used for?

HTTP stands for Hypertext Transfer Protocol, and it is used for communication between web browsers and web servers.

What is the simplified sequence of events when typing a URL into a web browser?

DNS looks up the IP address for the domain name -> device sends network requests -> routers forward packets through different paths -> server receives request and sends data back -> browser receives response and displays webpage.

What are the layers of abstraction in the Internet model from physical hardware to web communication?

Physical Internet (cables, fiber, wireless) -> IP (addresses and routing) -> TCP/UDP (how data is transported) -> DNS (translates domain names) -> HTTP (web communication).

What is scalability?

The ability of a system to continue working as it grows in size to support more devices, users, and data.

What is Net Neutrality?

The principle that Internet service providers should generally provide access to Internet content and services without unfairly favoring or blocking particular sources.

What is Internet Censorship?

Attempts to control, restrict, or suppress what people can access, publish, or view on the Internet.

What is the Digital Divide?

The gap between people who have access to modern information and communication technologies and those who do not.

What is a common test trap regarding the function of routers versus DNS?

Falsely assuming routers translate domain names into IP addresses; DNS handles domain name translation, while routers direct packets between networks.