Book summary “Internet”: summary

Introduction

You face a vast digital landscape that often feels overwhelming, confusing, and insecure. Navigating modern networks requires mastering complex tools while protecting your personal data from constant threats. Margaret Levine Young explains how global networks operate in "Internet".

Mastering the Internet requires understanding its core services, robust security practices, and practical tools for communication, commerce, and daily life.

The book guides you through hardware selection, safe browsing habits, and advanced communication methods. You learn how to connect devices, secure your system, and utilize web services effectively.

How can you choose the right connection and protect your data?

• What steps keep your system safe from online threats?
• How do you navigate the web and use email efficiently?

1. What Makes the Internet Work

The Internet is the world's largest computer network. It functions as a network of networks that allows two-way, egalitarian communication between any connected devices.

The Internet functions as a decentralized network of networks, connecting devices globally through standardized services and cloud computing.

Unlike broadcast television where the same information is sent everywhere, computer networks route specific messages to particular computers. Both sides can reply. The system spans the globe, rejects central control, and connects everything from massive corporate systems to tiny homemade setups and mobile devices.

The Internet evolved from the ARPANET project funded by the U.S. Department of Defense in 1969. It was designed to link military researchers and universities.

The ARPANET originally connected three computers in California with one in Utah.

Starting small, the project expanded across the continent and to Europe. In the 1980s, it grew into the early Internet with National Science Foundation funding. Commercial companies took over running the networks by 1990.

The Big Three Services

The core utility of the Internet rests on its Big Three services. You rely on these tools for daily communication and information retrieval.

• Electronic mail allows global text communication and mailing lists.
• The World Wide Web provides a global multimedia hyperlinked database navigated via browsers.
• Instant messaging programs provide pop-up text communication for fast exchanges.

The Internet is the most open network in the world. You can access it through companies, schools, libraries, or paid Internet service providers. Hardware has evolved to include netbooks, smartphones, tablets, and phablets that provide always-on pocket connections.

Cloud Computing

Cloud computing uses virtualization technology to let superfast physical servers operate as multiple independent virtual servers. These virtual servers scale on demand.

Virtualization was invented by IBM researchers in 1967 and used on mainframes for decades.

Because individual web servers are idle much of the time, data centers use virtualization to start and stop virtual servers as needed. This pools resources across time zones and geographic regions. You avoid the need to own physical hardware when operating websites.

2. Keeping Your System Safe Online

Connecting a computer to the internet exposes it to privacy erosion, security takeovers, and annoyances like spam within minutes. Unsavory actors view connected users as money trees, making cyberattacks a question of when rather than if. Privacy is compromised as advertisers and trackers monitor online activities, location, and purchases.

Connecting to the Internet exposes you to security threats, malware, and phishing schemes that demand robust passwords, firewalls, and cautious habits.

Recognizing Threats

Phishing emails trick users into revealing sensitive credentials by mimicking legitimate authorities and organizations. Phishers send alarming messages urging immediate account verification via malicious links that lead to spoofed login pages. Once credentials and personal data are entered, attackers can commit identity theft or financial fraud.

An email purporting to be from eBay Billing Department warns recipients about fake bids and asks them to click a link to verify account registration information within 48 hours.

Websites use cookies to maintain session data and shopping carts, but tracking cookies can monitor user behavior across multiple sites. A cookie is a small file stored on a user's computer containing website codes and addresses. While helpful for shopping and reservations, third-party tracking cookies allow advertising networks to map browsing habits.

Viruses and worms compromise computer systems by executing malicious payloads or exploiting network security flaws. Viruses typically spread via email attachments and execute payloads that log keystrokes or send spam. Worms propagate automatically across the network without user intervention by exploiting vulnerable software.

Spyware and adware are downloaded via web browsers or bundled free software to track user activity and display targeted advertisements. Users often install spyware unwittingly when downloading free utilities or visiting malicious sites. These programs can capture keystrokes, generate unwanted pop-up windows, and alter browser behavior.

Unsolicited bulk email imposes substantial financial and operational burdens on internet service providers and users alike. Because sending junk email costs virtually nothing, spammers flood the network with 100 billion messages daily, consuming bandwidth and server resources. Large ISPs find that 95 percent of incoming email is spam, and they allocate 2 dollars of monthly user fees to handling and cleaning up after it.

Essential Defenses

Robust passwords and password managers are essential for preventing unauthorized access to sensitive online accounts. Weak passwords based on dictionary words can be cracked rapidly by automated attack tools.

The authors once left a password set to the normal English word weather, and hackers broke into their computer in less than two hours.

Protect your accounts with these practices:

• Pick complex passwords that are long enough that no one can guess them.
• Never use as a password a word that occurs in the dictionary. Consider sticking a number or two into your password.
• Never use the same password for different accounts.
• Memorize your passwords and never write them down.
• Change your passwords frequently.

Defend against phishing with these rules:

• Assume that every email that leads you to a page seeking passwords or credit card numbers or other personal information is a phishing expedition.
• If the email purports to be from a company you’ve never heard of, ignore it.
• If the message says that it’s from a company with whom you have an account, go to the company’s website by typing the company’s URL into your browser, not by clicking a link in the email.

3. Assembling Gear and Connections

Selecting the right hardware, broadband connection, and protective software ensures reliable and secure high-speed access to the web.

You can connect to the Internet using a wide range of devices. The Internet is a collection of 100,000 separate networks, meaning connection methods depend on your equipment. You can buy a perfectly usable new computer for 300 dollars or less. The oldest personal computer that can still be adapted for some type of Internet connection dates back to 1980. Desktops require broadband or dial-up, while laptops, tablets, and smartphones can use Wi-Fi or cellular data.

Smartphones and cellular tablets require a monthly data plan for Internet use. These plans typically cost between $15 and $50 per month for a set amount of usage. Email and audio consume very little data, but streaming video can quickly max out your quota and incur extra charges. The iPhone debuted in 2007 and created a huge sensation.

Broadband Connections

Broadband connections such as DSL and cable provide fast, high-speed Internet access without tying up your regular phone line. DSL uses a phone line shared with regular phone services, while cable uses the local cable TV connection. Both offer speeds often exceeding 10 million bits per second. Basic high-speed cable or DSL costs about 30 dollars per month, while the fastest cable options reach 100 dollars per month. The lowest DSL speed adequate for most users is 640 Kbps or more.

Connecting a computer to broadband requires a modem and a network adapter. Cable modems are standardized enough that buying one for 90 dollars can save money over paying a 5 dollars per month rental fee. Computers connect to these modems using built-in Ethernet network adapters, wireless network adapters, or USB ports.

Public Wi-Fi networks in coffee shops and hotels lack encryption. Paid Wi-Fi access via mobile phone providers typically costs 6 dollars per hour, and typical hotel Wi-Fi charges 10 dollars per day. Anyone on the network can easily monitor your traffic.

You can connect to a wireless network using these steps:

• Open the Settings app.
• On iPhones and iPads, tap Wi-Fi.
• If Wi-Fi is turned off, turn it on by sliding its slider to On.
• When you see the list of networks, tap the one you want.
• If the Wi-Fi hotspot requires a password, your device asks you for it.

System Safety

A firewall acts as a barrier against hackers. It can be implemented using either operating system software or a dedicated hardware router costing approximately 40 dollars. Windows and Mac systems include built-in firewall software that should be kept turned on.

You can verify your firewall settings with these steps:

• Press the Windows key until you see the Windows 8.1 Start screen.
• Type firewall.
• Choose Windows Firewall.
• Look for the Windows Firewall state and make sure it is On.

Continuous protection against viruses and spyware is essential for keeping an Internet-connected system safe. Viruses and spyware sneak onto computers via email or web browsing. You should run active virus checkers with regularly updated definition lists, such as Windows Defender or Microsoft Security Essentials.

You can check your update status with these steps:

• Press the Windows key until you see the Windows 8 or 8.1 Start screen.
• Type update.
• Choose Windows Update to check whether automatic updates are turned on.

4. Navigating the Web and Browsers

Web browsers and secure URLs allow you to explore the World Wide Web, manage bookmarks, and protect your privacy through proper settings.

The World Wide Web operates as an information system on top of the Internet. Sir Tim Berners-Lee invented it in 1989 at CERN, creating HTTP, HTML, and URLs so users globally could navigate connected documents. The inventor was knighted in 2004. Every web resource uses a Uniform Resource Locator defining the access scheme, host computer, and file path.

Browsers help you explore these resources. Chrome holds about 60 percent of the web browser share, while Firefox captures 24 percent. Internet Explorer accounts for 10 percent.

You can move between pages by clicking links or typing a URL in the Address bar.

Browser Tools

Web pages consist of separate text and image components. Browsers cannot save an entire page as a single file, but you can copy text or save images directly.

• Select text with the mouse and press Ctrl+C (Command+C on the Mac) to save the text to the Clipboard.
• Position the cursor in a word processing program and press Ctrl+V (Command+V on the Mac) to paste the text.
• Right-click an image on a web page.
• Choose Save Image As in Firefox, Chrome, or Safari, or Save Picture As in Internet Explorer.
• Move to the desired folder, type a filename, and click the Save button.

Most internet content is copyrighted. Margaret Levine Young and fellow authors have visited the Google website thousands of times. National Public Radio at www.npr.org and the BBC website at www.bbc.co.uk provide news broadcasts in 43 languages using streaming audio and video features.

• Send an email message to the owner of the site before reusing text or pictures.
• Write to webmaster@domain.com, replacing domain.com with the domain name part of the page's web address if no direct address appears.

Managing Data

You can store frequently visited web addresses so you do not need to type them repeatedly. Browsers call these bookmarks in Firefox, Chrome, and Safari, or favorites in Internet Explorer.

• Click the Bookmark This Page star icon at the right end of the Address bar in Firefox or Chrome.
• Press Alt+C or click the Favorites icon and choose Add to Favorites in Internet Explorer.
• Open the Library window or Bookmark Manager to organize bookmarks into folders.
• Drag favorite sites into the Bookmarks Toolbar or Favorites Bar folder for one-click access.

Web forms gather data through text boxes, check boxes, and radio buttons. Secure web servers use encryption for sensitive transmissions like credit card numbers, indicated by a padlock icon.

• Type information into white fill-in text boxes.
• Check applicable square check boxes.
• Choose a single option from a set of round radio buttons.
• Select an entry from a scrollable list box.
• Click the Submit button to send the form data to the web server for processing.

Browsers can remember usernames and passwords, though this introduces risks on shared computers.

• Click Yes when the browser pops up a window offering to remember entered usernames and passwords.
• Navigate to browser Options or Preferences, select Security or Passwords, and check Remember Passwords for Sites or Offer to save your web passwords.
• Select the Use a Master Password check box in Firefox to require a single password at the start of every session.

Websites can store three or more cookies during a single visit. You can control these files through browser settings.

• Open browser Options or Preferences and navigate to the Privacy tab or History settings.
• Choose custom settings for history to allow cookies from sites.
• Set third-party cookies to be blocked or accepted only from visited sites.
• Adjust privacy sliders or check boxes to block third-party cookies and allow session cookies.

Browsers log your browsing history to help you retrace steps.

• Press Ctrl+H or navigate through the Menu to access the History tab or Library window.
• Select Clear Browsing History or Clear Recent History to delete past session data.
• Choose New Private Window in Firefox or Safari, InPrivate Browsing in Internet Explorer, or New Incognito Window in Chrome to browse without leaving traces.

Pop-up blockers suppress unrequested windows automatically.

• Access browser Options, Preferences, or the Privacy tab in Internet Options.
• Ensure the check box for blocking pop-up windows is selected.
• Click the Exceptions or Manage Exceptions button to add trusted web addresses that are allowed to show pop-ups.

Plug-ins handle advanced media and document types.

• Download essential plug-ins directly from official provider sites such as Adobe or Apple.
• Run the downloaded installer file to attach the plug-in to the browser.
• Access browser Add-ons, Extensions, or plugins pages (such as typing about:plugins in Chrome) to manage or disable installed plug-ins.

Executable files carry severe security risks and require caution.

• Find the desired file on the web and click the Download button.
• Choose a destination folder, such as the desktop or the default Downloads folder, in the Save dialog box.
• Open the downloaded file by double-clicking its filename or icon.
• Complete installation wizard prompts only if the software source is completely trusted.

5. Email, Social Media, and Communication

Effective communication via email, social networks, and messaging apps requires mastering server configurations, security rules, and etiquette.

Every email address uses the @ sign to separate the personal username from the domain name, which points to the mailbox location such as an ISP, employer, private domain, or webmail server. The president of the United States can be reached at president@whitehouse.gov, where president is the username and whitehouse.gov is the domain. Webmail stores your mailbox on the provider's server so you can check messages anywhere, though it may require internet access and be slower than dedicated desktop applications. About 20 years ago, two people simultaneously had the idea of creating web-based email.

• Using your web browser, go to the webmail service’s website.
• Look for a link named Create an Account or Sign Up Now or similar wording and follow the instructions to create your account.
• In Table 8-1, write down your email address and your password.

IMAP stores messages on the server to keep mail synchronized across multiple devices, whereas POP downloads and deletes messages from the server. Using IMAP allows a user to access the exact same set of folders and messages from home, work, or a phone, whereas POP pulls mail directly to a single computer. One or 2 megabytes is tight for mail storage, whereas 100 megabytes should be plenty.

Smartphones and tablets require specific account configurations to connect to email services via apps or built-in mail clients. Mobile devices on Android, iOS, or Windows can manage email by navigating settings menus to add accounts manually or through automated provider detection. Android 5.0 Lollipop combined all mail programs into the Gmail app.

• Android: Open the Settings Menu, go to Accounts, select Add account, and add your account details.
• iPhones and iPads: Choose Settings, Mail Contacts Calendars, Add Account, and select your provider.
• Windows phones and tablets: Display the App list, choose Settings, Email + Accounts, Add An Account, and follow instructions.

Major webmail providers use specific server addresses and port numbers for POP and SMTP configurations. When setting up desktop email programs manually, exact incoming and outgoing server names along with designated port numbers must be supplied. Gmail POP server uses pop.gmail.com on port 995. Gmail SMTP server uses smtp.gmail.com on port 587. Outlook.com POP server uses pop3.live.com on port 995. Outlook.com SMTP server uses smtp.live.com on port 587.

Email allows sending secondary copies to additional recipients publicly through CC or privately through BCC. The CC field sends carbon copies visible to everyone, while the BCC field conceals recipient addresses from other people receiving the message. Born before 1965 and remember carbon paper used in typewriters.

• Click the Write, New, or New Message icon or button.
• Fill in the recipient’s address in the To box.
• Add any Cc or Bcc addresses that you want the messages to go to.
• Type the subject in the Subject box.
• Type the message in the big box.
• Click the Send icon or button to send the message.

Email attachments and links can harbor malware, viruses, and phishing scams that mimic official organizations. Viruses frequently replicate by mailing themselves to contacts found in infected address books, while phishers use fake links to steal personal data. Viruses often automatically send copies of themselves to the first 50 people in an address book.

Email Management

Email lacks vocal tone and facial expressions, making misunderstandings common and requiring careful tone management. Writing in all capital letters simulates shouting, and subtle sarcasm often fails, coming across as annoying rather than funny. Excessive or pointless outrage is known as flaming and should be avoided by waiting before responding to obnoxious messages. 30 years of using email without regretting not sending an angry message.

• Watch the tone of your language when sending a message.
• Avoid using all capital letters to prevent looking like you are shouting.
• Wait until after lunch before replying to an offensive message to avoid flaming.

The vast majority of internet mail consists of unsolicited spam, requiring robust filtering mechanisms across webmail, desktop clients, and mobile apps. Email systems automatically sort bulk mail into junk or spam folders, but users must periodically review these folders to catch falsely categorized good messages known as ham. Upward of 90 percent of all mail is spam.

• Choose Mail, Preferences, and click the Junk Mail icon in Apple Mail.
• Check Enable Junk Mail Filtering if it is not already checked.
• Select Move It to the Junk Mailbox option.
• Select the box to exempt senders in your address book.
• Select Trust Junk Mail Headers Set by My Internet Service Providers.

Replying to emails requires careful attention to recipient lists and proper trimming of quoted text to provide necessary context without clutter. Mail programs automatically pre-address replies and include original text, but users must verify whether the response goes to an entire mailing list or just an individual. Editing the quoted text to include only relevant material prevents confusing the recipient.

• Look at the To line to verify if the recipient group is correct before sending a reply.
• Edit the quoted text to include only the relevant material.
• Type your message above the quoted text from the original message and click Send.

Email systems limit message sizes, requiring alternative file transfer services or cloud drives for transmitting large documents and videos. Because mail servers often restrict total message sizes, users can upload large files up to 2GB to dedicated file transfer websites or cloud storage providers and share the resulting links via email. There is a 4MB typical limit for email messages including attachments.

• Use a file transfer website like dropbox.com or WeTransfer.com to send large files.
• Upload video files to YouTube or Vimeo and email the web address.
• Upload the file to Google Drive or OneDrive and share it with friends.

Social Networks

Social networking sites allow users to create profiles and connect with contacts, with different platforms serving distinct personal and professional audiences. Platforms like Facebook serve diverse general audiences, LinkedIn focuses specifically on professional networking and job searches, and Google+ organizes connections into circles. More than 700 million people use Facebook.

• Ask your friends and colleagues which networks they belong to before joining.
• Think of people you expect to find on a site and search for them before creating an account.

Managing privacy settings on social networks allows users to control audience visibility, though personal data remains accessible to platform advertising systems. Facebook provides configuration options to limit post visibility to specific custom groups, friends, or the general public. Platform mechanics utilize user posts and personal information to serve targeted advertisements alongside the news feed.

• Click the Privacy Shortcuts icon in the upper right corner of every page and choose See More Settings.
• Select how wide a circle of people can see your friend list or send you messages.
• Click the Edit button to the right of a setting to change your choice, make modifications, and click Close.

10 Key Ideas

1. The Internet functions as a decentralized network of networks, connecting devices globally through standardized services and cloud computing.
2. Connecting to the Internet exposes you to security threats, malware, and phishing schemes that demand robust passwords, firewalls, and cautious habits.
3. Selecting the right hardware, broadband connection, and protective software ensures reliable and secure high-speed access to the web.
4. Web browsers and secure URLs allow you to explore the World Wide Web, manage bookmarks, and protect your privacy through proper settings.
5. Effective communication via email, social networks, and messaging apps requires mastering server configurations, security rules, and etiquette.
6. Robust passwords and password managers are essential for preventing unauthorized access to sensitive online accounts.
7. A firewall acts as a barrier against hackers and can be implemented using either operating system software or a dedicated hardware router.
8. Browsers log your browsing history to help you retrace steps and offer private browsing modes to explore the web without leaving traces.
9. Email systems automatically sort bulk mail into junk or spam folders, but users must periodically review these folders to catch falsely categorized good messages known as ham.
10. Managing privacy settings on social networks allows users to control audience visibility, though personal data remains accessible to platform advertising systems.