Internet & WWW
01
The Internet is one of the 7 Big Ideas of the CS Principles curriculum. This course focuses on three key questions about the Internet:
What is the Internet, how is it built, and how does it work?
What aspects of the Internet's design and development have enabled it to grow so large and be so influential?
How does cybersecurity affect what we do on the Internet?
The Internet and the World Wide Web have had a tremendous influence on our world and our lives. Yet, most people do not really understand what the Internet is and how it works.
Let's begin with a common misconception. Most people do not distinguish between the Internet and the World Wide Web, but they are two completely different things.
Technical Terminology
World Wide Web (WWW) - an application that runs on the Internet. The WWW is a system of interlinked resources, documents, images, sounds, videos, data files, that are stored on the Internet and can be accessed through a browser (an internet application based on HTTP)
Internet (capital "I") - the underlying global network that supports the WWW and many other applications, and consists of many different local networks that are connected together by various hardware devices governed by the Internet Protocal Suite (IPS)
protocol - a system of rules that govern the behavior of some system
TCP/IP - TCP/IP (Transmission Control Protocol/Internet Protocol) is the suite a protocols that determine the behavior of the Internet
HTTP - HTTP (HyperText Transfer Protocol) is the protocol that controls the behavior of the Web
The Cloud - a popular term for the Internet and its applications used largely in marketing and advertising
Tim Berners-Lee - invented the World Wide Web (WWW)
higher level of abstraction - Berners-Lee refers to the WWW as a 'higher level of abstraction' in the sense that the HTTP protocol uses lower level protocols, such as TCP, to provide a set of tools that simplifies the handling of multi-media resources
open standard - An open standard is a standard (such as TCP, HTTP) that is not owned or controlled by a private entity. It stands in contrast to 'proprietary' materials', which are owned or controlled by a private entity
Facebook, Google, Twitter, Dropbox are often referred to as cloud applications. They could also be called Internet applications. App Inventor is another example of a cloud application.
Computing Ethics
Innovations in computing have raised legal and ethical concerns. From commercial access to music and movie downloads and streaming and open source and licensing of software and content, how individuals use computers is becoming more and more important.
According to the Wikipedia article, Ten Commandments of Computer Ethics, here are the 10 Commandments for ethical behavior when using computers:
You shall not use a computer to harm other people.
You shall not interfere with other people's computer work.
You shall not snoop around in other people's computer files.
You shall not use a computer to steal.
You shall not use a computer to bear false witness.
You shall not copy or use proprietary software for which you have not paid without permission.
You shall not use other people's computer resources without authorization or proper compensation.
You shall not appropriate other people's intellectual output.
You shall think about the social consequences of the program you are writing or the system you are designing.
You shall always use a computer in ways that ensure consideration and respect for your fellow humans.
Read this short case study about a Silicon Valley social networking company collecting users "Contacts" data and storing it on their servers.