Module 6: Networking and Communication

1. A network is two or more computers connected so they can share data and resources. Networking is why one file, one printer, or one internet connection can serve a whole classroom.
2. LAN vs WAN: a local area network (LAN) covers one building or campus — the Largo HS network is a LAN. A wide area network (WAN) connects LANs across cities or countries. The internet is the largest WAN: a worldwide network of interconnected networks.
3. The internet and the World Wide Web are not the same thing. The internet is the physical network of networks (started as ARPANET in 1969). The web is a service that runs on top of the internet — pages linked by hyperlinks, invented by Tim Berners-Lee in 1990 and opened to the public in 1991.
4. TCP/IP is the set of rules (protocols) every device follows to communicate on the internet. IP gives every device an address; TCP breaks messages into packets, numbers them, and makes sure they all arrive and are put back in order.
5. Packet switching: a message is cut into small packets that can travel different routes and are reassembled at the destination. That is why the internet keeps working when one path is busy or broken.
6. An IP address identifies a device on a network (IPv4 looks like 192.168.1.10; IPv6 is longer because IPv4 addresses ran out). DNS — the Domain Name System — is the internet's phone book: it translates names like pgcc.edu into IP addresses so people can use names instead of numbers.
7. Home and school hardware: the modem connects your building to your internet service provider (ISP); the router sends data between your local network and the internet and gives each device a local address; a switch connects wired devices inside the LAN; a wireless access point broadcasts Wi-Fi.
8. Wired vs wireless: Ethernet cables and fiber optic lines are wired — fast, reliable, harder to intercept. Wi-Fi, Bluetooth (short range, device to device), and cellular (4G/5G) are wireless — convenient, but shared airspace means slower speeds when crowded and more need for security like WPA passwords.
9. Bandwidth measures how much data can move across a connection in a given time, usually in megabits per second (Mbps). Latency is the delay before data starts moving. A video call needs both: enough bandwidth and low latency.
10. Client-server and cloud: your device (the client) requests pages, files, and email from servers. Cloud computing means those servers belong to a provider (Google Drive, iCloud, Canvas) so you can reach your files from any device with a connection — nothing is stored only on one machine.
11. Common protocols and acronyms you will see on the Network Acronym Soup assignment: HTTP/HTTPS (web pages; the S means encrypted), URL (a web address), ISP (internet service provider), VPN (virtual private network — an encrypted tunnel across a public network), VoIP (voice calls over the internet), MAC address (a device's hardware address).
12. Metcalfe's Law: the value of a network grows with the square of the number of users — one phone is useless, two can call each other, a billion can reach everyone. That is why social networks, email, and messaging apps grew so fast.
13. Module 6 items: Class Activity – Networks Reflection Assignment (30), Network Acronym Soup Assignment (20), and Module 6 Quiz (20) — 70 points, the week of Oct 5. Module 7 (Databases) follows the week of Oct 12.

Raise your hand. Mr. James gets a message right away and can help you remotely. Nothing else is stored — just your last name, grade, and where you're stuck.

Ask at home: How does a message get from your phone to a friend's phone across town?

En español: ¿Cómo llega un mensaje desde tu teléfono al teléfono de un amigo al otro lado de la ciudad?