How the Internet Works: Services, Networks, and Tools

1. What is the Internet?

The Internet is a decentralized global network of computers connected through communication protocols using cables, fiber optics, and wireless connections. It offers many services, such as:

• Web browsing (WWW)
• Email (POP mail and webmail like Gmail)
• Forums, chats, and instant messaging
• File transfer (FTP) and P2P sharing (eMule, BitTorrent, Dropbox)
• Voice and video calls (VoIP) using Skype, WhatsApp, etc.
• Online radio, TV, press, shopping, banking, distance learning, and job searching.

2. How Information Travels on the Internet

When a user types a web address:

1. The browser sends the request via HTTP.
2. The router forwards it to the ISP (Internet Service Provider).
3. The DNS server translates the domain name (e.g., www.example.com) into an IP address (e.g., 77.73.203.21).
4. Using the TCP/IP protocol, data is divided into packets, sent through possibly different routes, and reassembled at the destination.
5. The server responds with HTML code, which the browser interprets and displays as a webpage.

3. The Online World

The Internet has made many daily activities easier and faster:

• Online shopping (with PayPal and secure payment)
• eGovernment services (taxes, official documents, DNI electrónico)
• Distance learning
• Job hunting (Infojobs, LinkedIn)
• Communication via chats, video calls (Skype, WhatsApp)
• Social networks
• Downloading and sharing files (WeTransfer, Dropbox)
• Multimedia: online radio, TV, and newspapers

4. Collaboration Tools: Document Repositories

These are websites that allow users to store and share any type of digital files (photos, videos, documents, presentations). They eliminate the need for large local hard drives.

Advantages: Everyone works on the latest version, easy collaboration, and simple distribution of documents.

5. Social Networks

A social network is a structure based on relationships between people that enables different types of exchange (social, professional, educational, etc.).

Types of Social Networks

• Horizontal/General: Facebook, MySpace, Twitter, Hi5 (for general use)
• Vertical/Specialized:
  • Professional: LinkedIn, Xing
  • Educational: Ning, EducaRed
  • For children: Mi Cueva

Social bookmarking uses tags to organize, search, and share interesting links and content.

6. Examples of Tools and Services

Document Repositories & Multimedia

• Images: Google Photos, Flickr, Pinterest, Instagram, Panoramio
• Video: YouTube, Vimeo
• Presentations: SlideShare, Prezi, SlideRocket
• Documents: Scribd, Issuu
• Music: Spotify, Podomatic

Online Office Suites (No Installation Needed)

• Google Docs (documents, spreadsheets, presentations)
• Zoho, Evernote, Z-Cubes, OfficeZilla, EyeOS

Examples of Social Networks

• General: Facebook, WhatsApp, Twitter, MySpace, Hi5, Periscope
• Professional: LinkedIn, Xing
• Educational: Ning, EducaRed, LibraryThing
• Bookmarks: Delicious