Big Idea 4: Interconnected Computing Systems

The Internet

The physical network of connected computing devices (hardware and infrastructure).

World Wide Web (WWW)

A system of linked pages, programs, and files accessed via the Internet using protocols like HTTP.

Network of Networks

The structure of the Internet, composed of multiple interconnected networks.

Computing Device

Any machine that can run a program (e.g., computer, smartphone, smart thermometer).

Computing System

A group of computing devices and programs working together for a common purpose.

Dynamic Routing

A property of the Internet where paths between devices can change based on conditions like traffic congestion.

Packet Switching

A method where large files are broken into small packets for transmission over the Internet.

Packets

Small chunks used in packet switching to transmit data, each wrapped with metadata.

Protocol

An agreed-upon set of rules for devices from different manufacturers to communicate.

Open Protocols

Standardized, public protocols that are free to use, allowing the Internet to scale.

IP (Internet Protocol)

Assigns unique addresses to devices and plays a role in routing.

TCP (Transmission Control Protocol)

Ensures reliability by checking if all packets arrive and requesting resends if not.

UDP (User Datagram Protocol)

Sends packets quickly without ensuring error checking or ordering, used where speed is prioritized over accuracy.

HTTP(S) (Hypertext Transfer Protocol)

Requests and transmits web pages, facilitating communication between client and server.

DNS (Domain Name System)

Translates human-readable domain names into IP addresses.

Fault Tolerance

The ability of a system to keep operating properly even when some components fail.

Redundancy

The inclusion of extra components in a system to provide backup in case of a component failure.

Sequential Computing

Operations performed in order, one at a time.

Parallel Computing

Breaking a program into smaller sections that can be executed simultaneously on multiple processors.

Distributed Computing

Multiple independent computers working on a shared problem, allowing large scale operations.

Speedup

A measure of the efficiency gained by running processes in parallel versus sequentially.

Latency

The time it takes for a single bit of data to travel from sender to receiver.

Bandwidth

The maximum amount of data that can be transmitted in a fixed amount of time.

Overhead

The extra time required to manage parallel processes, which can slow down execution.

Scalability

The ability of a system to handle a growing amount of work or its potential to accommodate growth.

Hierarchy (in DNS)

The structured levels at which DNS servers operate to resolve domain name queries.

Dynamic Routing vs Static Routing

Dynamic routing changes based on current network conditions, while static routing has fixed paths.