Networking - Introduction 1st Class

Questions in Red, Light bulbs in purple, Green is answered

Networking

the action or process of interacting with others to exchange information and develop professional or social contacts.

computer word: people are behind the telephone and computer connections.

-networking is the process of connecting two or more devices to communicate and share resources. It involves establishing a communication link between devices, allowing them to exchange data, share files, and utilize networked resources like printers or servers. 

Two main types of connections

Wired: This uses physical cables (like Ethernet cables) to connect devices.

Pros:

• ✅ Faster speeds

• ✅ More stable and reliable

• ✅ More secure (harder to hack physically)

Common Uses:

• Office computers

• Servers in data centers

• Gaming setups

Wireless: Wireless Networking (Wi-Fi)

This uses radio waves to connect devices without cables.

Pros:

• ✅ More flexible — no wires!

• ✅ Great for phones, tablets, and laptops

• ✅ Easier setup

Common Uses:

• Home internet

• Public hotspots (cafes, airports)

• Smartphones, smart TVs, smart devices

communication

- Communication is just the way people share messages with each other sharing what they think or feel between multiple people and these types of interactions can happen between one to one person, a group, or multiple people.

Some types of communication:

Communication Type (Connection Style)	How It Relates to Data Transfer (Unicast, Broadcast, etc.)	Explanation
Point-to-Point	✅ Matches with Unicast	One device talks to only one other device. A dedicated link between them.
Broadcast	✅ Matches with Broadcast	One device sends a message to every device on the network (local area).

Devices we use in networking

Router

Switch

Firewall

Access Point

Switch

A switch is a physicals device that connects other devices in a network like computers, printers and servers. It makes sure that the data goes to the right place by using MAC addresses—like a smart mail sorter that sends the message to the exact person who needs it.

For switches, how to the sending devices work?

Step-by-Step with the Switch:

1. Computer A prepares the data

   • You drag and drop the PDF file into a shared folder, or send it over the network using File Sharing.

2. The data gets broken into packets

   • The file is divided into small chunks of data called packets.

   • Each packet has a source MAC address (Computer A) and a destination MAC address (Computer B).

3. Packets are sent to the switch

   • These packets don’t go directly to Computer B.

   • They go to the switch, because both A and B are plugged into the switch (not each other).

4. The switch checks the MAC address

   • The switch looks up Computer B’s MAC address in its MAC address table.

   • It finds out which port Computer B is connected to.

5. The switch forwards the packets

   • It sends the packets only to Computer B, not to everyone else.

   • This is more secure and efficient than broadcasting.

6. Computer B receives the file

   • Computer B puts all the packets back together and rebuilds the PDF file.

   • Now it can open and read the file.

Router

A router is like a smart traffic controller. It connects your home or office network to the internet, and it makes sure your data gets to the right place using IP addresses.

Firewall

A firewall is a network security device that monitors traffic to or from your network. It allows or blocks traffic based on a defined set of security rules.

WAN (Wide Area Network)

Connecting a group of LANS across multiple cities

MAN ( Metropolitan Area Network)

MAN stands for Metropolitan Area Network. It is a computer network that connects number of LANs to form larger network, so that the computer resources can be shared

Firewalls can prevent someone from the outside , like WAN to access the network. How?

A firewall is like a security guard for your network.

• It monitors incoming and outgoing data (like a gatekeeper)

• It decides what is allowed in or blocked

WAN to LAN: Why Protection Is Needed

• The WAN (Wide Area Network) = the internet

• Your LAN (Local Area Network) = your private network (home or office)

How is the internet a WAN?

A Wide Area Network (WAN) is any network that spans a large geographical area—like cities, countries, or even continents.

The Internet is the largest WAN in the world. It's made up of millions of smaller networks (homes, schools, businesses) all connected together. These networks communicate through routers, switches, and service providers to form one global system — the Internet.

So, the Internet is a WAN, just on a massive, global scale.

Access point

-It allows devices to connect to the network withouttthe ue of physical cables.

-In access point lets Wi-Fi devices (like phones, laptops) connect to a network — even if the network is using cables.

-“It acts as a bridge, allowing devices like laptops, smartphones, and tablets to communicate with the network without a physical cable.”

-Everyday Example:

At a coffee shop:

• The access point is what gives you the Wi-Fi signal.

• You connect your phone to “CoffeeShop_WiFi”

• Now your phone is part of their network — without any wires

The AP sends out a Wi-Fi signal—(It—-broadcasts it)
Any device nearby (like your phone or laptop) can connect to the Wi-Fi and use things like:

• The internet

• Printers

• Shared files