Module 6 — Networking and Communication

Module 6 · week of 10/05/2026 · Tech+: Infrastructure — networking basics: LAN vs WAN, wired (Ethernet) vs wireless (Wi-Fi, Bluetooth, cellular), IP addresses, DNS, routers and modems, bandwidth, and cloud services. · Download .docx

Objectives

Explore data communications concepts and basic principles of connectivity including wired and wireless technologies.

Key terms

Network: Two or more computers connected so they can share data and resources.
LAN: Local area network — connects computers within one building or campus.
WAN: Wide area network — connects networks across cities, states, or countries; the internet is the largest WAN.
Internet: The worldwide network of interconnected networks; began as ARPANET in 1969.
World Wide Web: A service that runs on the internet — pages connected by hyperlinks; invented by Tim Berners-Lee in 1990.
Protocol: A set of rules that lets computers communicate with each other.
TCP/IP: The core internet protocols: IP addresses each device; TCP delivers packets reliably and in order.
Packet: A small piece of a message that travels the network separately and is reassembled at the destination.
IP address: A number that identifies a device on a network (IPv4 like 192.168.1.10; IPv6 is longer).
DNS: Domain Name System — translates a name like pgcc.edu into an IP address.
ISP: Internet service provider — the company that connects your home or school to the internet.
Modem: The device that connects a building's network to the ISP's line.
Router: The device that sends data between your local network and the internet and assigns local addresses.
Switch: A device that connects wired computers inside a LAN.
Ethernet: The standard for wired local networks — cables plugged into a switch or router.
Wi-Fi: Wireless networking that connects devices to a LAN without cables.
Bluetooth: Short-range wireless connection between two devices (earbuds, keyboard, phone to car).
Bandwidth: How much data can move across a connection in a given time, usually in Mbps.
Latency: The delay before data starts moving across a connection.
Client-server: A model where the client (your device) requests a service and the server provides it.
Cloud computing: Storing files and running services on a provider's servers so you can reach them from any device.
HTTP / HTTPS: The protocol web browsers use to fetch pages; HTTPS is the encrypted version.
URL: Uniform Resource Locator — the address of a page or file on the web.
VPN: Virtual private network — an encrypted tunnel that carries your traffic safely across a public network.
VoIP: Voice over IP — phone calls carried over the internet instead of phone lines.
MAC address: The unique hardware address built into a device's network adapter.
Metcalfe's Law: The value of a network grows with the square of the number of users connected to it.

The concept

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

Worked examples

Example 1: You type pgcc.edu into Chrome. List, in order, what the network does before the page appears on your screen. — 1) The browser asks DNS to translate pgcc.edu into an IP address. 2) The browser sends an HTTPS request to that address; the router passes it from the Largo LAN through the modem to the ISP and across the internet (WAN). 3) The web server breaks the page into packets and sends them back by TCP/IP. 4) Your device reassembles the packets and the browser displays the page.

Example 2: Every Chromebook in Room 105 is on Wi-Fi and a video keeps freezing during class. Name two possible causes using this module's vocabulary and one fix for each. — Cause 1: not enough bandwidth — 30 devices sharing one access point's airspace. Fix: plug the teacher station into Ethernet, or move half the class to a second access point. Cause 2: high latency or a weak Wi-Fi signal far from the access point. Fix: move closer or lower the video quality. Either way, wired Ethernet is faster and more reliable than shared wireless.

Example 3: The Network Acronym Soup assignment asks what LAN, WAN, DNS, ISP, and VPN stand for and what each one does. Give all five in one sentence each. — LAN — local area network, one building or campus. WAN — wide area network, connects LANs across long distances; the internet is the largest one. DNS — Domain Name System, turns names into IP addresses. ISP — internet service provider, the company that connects you to the internet. VPN — virtual private network, an encrypted tunnel that protects your traffic on a public network.

Common mistakes

"The internet and the web are the same thing." The internet is the physical network of networks (ARPANET, 1969). The World Wide Web is a service that runs on it — linked pages, invented by Tim Berners-Lee in 1990.
"Wi-Fi is the internet." Wi-Fi is wireless networking inside a LAN. The internet is reached through the router and modem to the ISP. A device can have full Wi-Fi bars and no internet.
"The router and the modem are the same box." The modem connects the building to the ISP's line; the router sends data between the local network and the internet and gives devices local addresses. Many home units combine both, but the jobs are different.
"A slow video means the Wi-Fi is broken." Usually it is bandwidth shared by too many devices, or latency. Ethernet is faster and more reliable than shared wireless.

Self-check

Try each one before you look. A miss here costs nothing and tells you exactly what to reread.

1. A network that connects computers within a single building is called a:

2. The internet is best described as:

3. What is the difference between the internet and the World Wide Web?

4. What does an IP address identify?

5. Which service translates a name like pgcc.edu into an IP address?

Canvas is the official record. This companion enhances the PGCC curriculum; it does not replace it. Last name and class year only. Students with a 504 plan or IEP: your accommodations apply.

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