Internet and Web Essentials Summary & Study Notes

🌐 The Internet

The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals. It originated as ARPANET in September 1969 with two main goals: to allow scientists at different locations to share information and to function even if part of the network were disabled by a disaster. Today, millions of hosts connect to the Internet.

🔌 Connecting to the Internet

Wired connections attach a computer or device via a cable to a communications device, while many devices use a wireless modem or other device to connect wirelessly. An Internet service provider (ISP) is a business that provides access to the Internet for individuals and organizations. Bandwidth represents the amount of data that travels over a network and is commonly described in megabytes ($MB$) or gigabytes ($GB$); for reference, $MB$ is approximately 1 million characters and $GB$ is approximately 1 billion characters.

🧭 IP Address & Domain Names

An $IP$ address is a sequence of numbers that uniquely identifies a computer or device on the Internet. A domain name is a text-based name that corresponds to the $IP$ address. A Domain Name System (DNS) server translates the domain name into its associated $IP$ address. The Internet’s original scheme used IPv4, but IPv6 lengthened the addresses, exponentially increasing the number of available addresses. For example, an IPv4 address might look like 192.0.2.1, while an IPv6 address looks like 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

🕸️ The World Wide Web

The World Wide Web (WWW), or web, is a worldwide collection of electronic documents (webpages). A website is a collection of related webpages, and a web server is a computer that delivers requested webpages to your computer. Web 2.0 refers to websites that allow users to share personal information, modify website content, and provide applications through a browser.

🌐 Browsers & Web Addresses

A web browser is an application that enables users with an Internet connection to access and view webpages on a computer or mobile device. A home page is the first page that a website displays, and current browsers typically support tabbed browsing. A webpage has a unique address called a web address or URL.

💾 Web Apps & Mobile Apps

A web app is an application stored on a web server that you access through a browser – web app hosts usually provide storage for users’ data and information on their servers, known as cloud storage. A mobile app is an application you download from a mobile device’s app store to a smartphone or tablet.

🗂 Types of Websites

There are several types of websites: Search engine software that finds websites, web pages, images, videos, news, maps, and other information related to a topic; Online social network where members share interests, ideas, stories, photos, music, and videos with other registered users; Informational and research sites; Media sharing and Bookmarking sites that enable users to manage and share media or links; and mass media sites for News, weather, sports, etc. Other types include Educational, Business, Governmental, Blogs, Wiki and collaboration sites, Health and fitness, Science, Entertainment, Banking and finance, Travel and mapping, and E-commerce.

🎨 Digital Media on the Web

Multimedia refers to any application that combines text with media. Graphic formats include BMP, GIF, JPEG, PNG, and TIFF. An infographic is a visual representation of data designed to communicate quickly. Animation is the appearance of motion created by displaying a series of still images in sequence. Audio includes music, speech, or any other sound, often compressed to reduce file size. You listen to audio on your computer using a media player. Video consists of images displayed in motion. Virtual reality (VR) is the use of computers to simulate a real or imagined environment that appears as a three-dimensional space. A plug-in or add-on is a program that extends the capability of a browser.

📧 Email & Other Internet Services

Email is the transmission of messages and files via a computer network. An email program lets you create, send, receive, forward, store, print, and delete messages. An email list is a group of email addresses used for mass distribution of a message. Instant messaging services notify you when one or more of your established contacts are online and then allow you to exchange messages or files or join a private chat room with them. A chat is a real-time typed conversation that takes place on a computer or mobile device with many other online users. A chat room is a website or application that permits users to chat with others who are online at the same time. An online discussion is an online area where users have written discussions about a subject. VoIP (Voice over IP) enables users to speak to other users via their Internet connection. FTP (File Transfer Protocol) is an Internet standard that permits file uploading and downloading to and from other computers on the Internet; many operating systems include FTP capabilities, and an FTP server is a computer that allows users to upload and/or download files.

🧭 Netiquette

Netiquette is the code of acceptable Internet behavior. Following netiquette helps maintain respectful, productive online interactions and reduces misunderstandings.