AP Comp Sci Unit 2

Computing Device

A physical device that can input, process, store, or output data.

Computing System

A group of computing devices and software that work together to accomplish a purpose.

Computing Network

Two or more computing devices connected to share data and resources.

Path

A route that data takes through a network from a sender to a receiver.

Bandwidth

The maximum amount of data that can be transmitted over a network in a given amount of time.

Protocol

A set of rules that allows devices to communicate with each other.

IP Address

A unique numerical address used to identify a device on a network.

Internet Protocol (IP)

A protocol that addresses and routes packets so they can travel between networks.

Router

A device that forwards data packets between networks toward their destinations.

Packet

A small piece of data sent across a network, containing data and addressing information.

Redundancy

Having extra connections, routes, or resources available as backups.

Fault Tolerant

The ability of a system to continue operating when part of it fails.

HTTP (Hypertext Transfer Protocol)

A protocol used to request and transfer web pages and other web resources.

Domain Name System (DNS)

A system that translates domain names, such as google.com, into IP addresses.

Internet

A worldwide network of interconnected networks that allows devices to communicate.

World Wide Web (WWW)

A collection of linked web pages and other resources accessed through the Internet.

Digital Divide

The gap between people who have access to modern technology and the Internet and those who do not.

Software Application

A program designed to help users perform specific tasks.

Operating System

Software that manages a computer's hardware and resources and allows applications to run.

TCP (Transmission Control Protocol)

A protocol that provides reliable data delivery by detecting missing packets and retransmitting data when needed.

UDP (User Datagram Protocol)

A protocol that sends data quickly with less overhead but does not guarantee delivery or order.

Metadata

Data that provides information about other data, such as its source, destination, or size.

Scalability

The ability of a system or network to grow and handle more devices, users, or data.

TCP vs. UDP

TCP prioritizes reliable delivery; UDP prioritizes speed and low delay.

IP vs. TCP

IP handles addressing and routing packets; TCP helps ensure reliable, ordered data delivery.

Purpose of Packets

Data is divided into smaller pieces so it can be transmitted efficiently across networks.

Why Packets May Take Different Routes

Routers can send packets along different available paths depending on network conditions and failures.

What Happens When Packets Arrive Out of Order?

TCP can rearrange data into the correct order before delivering it to the application.

What Happens When a Packet Is Lost?

TCP can detect missing data and request retransmission; UDP does not guarantee retransmission.

Reliable Transmission vs. Fast Transmission

Reliable transmission focuses on delivering data correctly; fast transmission focuses on minimizing delay.

Why Is Redundancy Important?

Backup connections and routes allow communication to continue if another connection fails.

How Does Fault Tolerance Work on the Internet?

If a router or connection fails, packets may travel through an alternative route.

Example of Fault Tolerance

A website stays available because another server takes over when one server fails.

Why Doesn't the Internet Depend on One Connection?

Multiple connections and routes allow data to travel even when some parts of the network fail.

How Do Standardized Protocols Help the Internet Grow?

They allow devices made by different manufacturers to communicate using shared rules.

How Can the Internet Support More Devices?

New networks, connections, and infrastructure can be added without replacing the entire Internet.

How Does Data Travel Across the Internet?

Data is divided into packets, addressed using IP addresses, and forwarded by routers across networks.

Do Packets Always Take the Shortest Path?

No. Packets may take different available routes based on network conditions and routing decisions.

How Does Bandwidth Affect Network Performance?

Higher bandwidth allows more data to be transmitted per second; limited bandwidth can slow transfers.

What Is Network Congestion?

When too much data competes for network resources, causing delays and slower performance.

Internet vs. World Wide Web

The Internet is the network infrastructure; the Web is a service that uses the Internet to access linked pages and resources.

Is the World Wide Web the Same as the Internet?

No. The Web uses the Internet, but the Internet also supports other services.

What Happens When You Enter a Domain Name?

DNS translates the domain name into an IP address so the device can locate the destination.

When Is TCP Appropriate?

When reliable delivery matters, such as transferring files or loading web pages.

When Is UDP Appropriate?

When speed and low delay matter, such as live broadcasts, online gaming, or real-time calls.

Why Might Live Video Use UDP?

Small delays can be more disruptive than occasional lost data, so speed may be prioritized.

What Happens When Many Users Access a Website?

Network congestion or limited server capacity may make the website slower.

How Can Extra Network Connections Improve Reliability?

They provide alternative routes for packets if a connection fails.

What Is the Role of a Router?

It forwards packets toward their destinations using available network routes.

What Information Does a Packet Contain?

A portion of the data and information needed to deliver it, such as source and destination addresses.

What Is the Role of IP Addresses in Communication?

They identify the source and destination devices so packets can be routed correctly.

What Is the Role of HTTP?

It allows a browser or other client to request web resources from a server.

What Is the Role of DNS?

It helps devices find the IP address associated with a domain name.

What Is the Role of Protocols in Networking?

They establish shared communication rules so devices can exchange and interpret data.

What Is the Digital Divide?

Unequal access to computers, Internet service, and other digital technologies.

Streaming Music or Video When Packets Are Lost

TCP may retransmit missing data, while real-time streaming may use UDP or buffering to reduce interruptions.

A Network Connection Fails but Communication Continues

Redundancy and alternative routes allow packets to reach their destination through another path.

A Website Remains Online After a Server Fails

Fault tolerance allows another server to continue providing the service.

Adding More Devices to a Network

Scalability allows a network to expand as more devices and users are adde