Topic 1(Introduction to Networking)

Host/End Device

Every computer on a network
is called?

Servers

are computers that
provide information to end
devices:
• email servers
• web servers
• file server

Clients

are computers that
send requests to the servers to
retrieve information:
• web page from a web server
• email from an email server

Transmission Media

Connect devices together

End devices

Where communication starts or ends

Layer 1 devices

Focus on signal transmissions

Computers, Mobile phones, Printers/Scanners, and Servers

give me examples of end devices

cables, connectors, repeaters, hubs

give me examples of layer 1 devices

File Server

stores corporate and user files.

Web Server

Runs web server software

Email Server

Runs email server software.

Peer-to-Peer

• A device can act as both a client and a server.

• Best suited for very small networks due to limited scalability and management.

Local Area Network

What does “LAN” stand for

Wide Area Network

What does “WAN” stand for

Switches, Bridges, Network Interface Cards

Examples of Layer 2 devices

Layer 1

• Definition: Moves raw bits (0s and 1s) as electrical signals, light pulses, or radio waves across physical media.

• Key idea: It’s the wires, connectors, and signals — no meaning, just transmission.

Layer 2

• Definition: Packages those bits into frames and uses MAC addresses to deliver data reliably between devices on the same local network.

• Key idea: It’s the local delivery system — making sure data reaches the right device in your LAN.

Layer 3

• Definition: Organizes frames into packets and uses IP addresses to route data across different networks.

• Key idea: It’s the global delivery system — making sure data travels from one network to another, anywhere in the world.

Media Access Control Adress

What does MAC stand for

MAC Adresses

• It’s a unique hardware ID built into your device’s network card (like the Wi‑Fi adapter or Ethernet port).

• Think of it as your device’s fingerprint on a local network — it identifies which exact machine should receive the data.

Routers, Firewalls, Layer 3 switches, Gateways

Examples of Layer 3 devices