IP Addresses, Routers & Switches (Core Concepts)

Every device on a network needs an address and a way to reach other devices. Understanding these core building blocks makes every other networking topic easier to follow.

• IP address: A unique numeric address (e.g. 192.168.1.15) identifying a device on a network, similar to a postal address.
• Router: Connects your local network to the internet and directs traffic between networks.
• Switch: Connects multiple devices within the same local network (e.g. several office computers) so they can communicate directly.
• Private vs public IP: Devices inside your home/office typically get a private IP (e.g. starting with 192.168.); your router has one public IP shared with the internet.

Practical Skill: Find your own device's IP address and your router's IP address, and identify whether they're on the same private network.

=== FINDING YOUR IP ADDRESS (Windows) ===Open Command Prompt and run:  ipconfig Look for:  IPv4 Address. . . . . . . . . . . : 192.168.1.15  Default Gateway . . . . . . . . . : 192.168.1.1   (this is your router) === FINDING YOUR IP ADDRESS (Phone) ===Settings -> Wi-Fi -> tap the connected network -> IP address === KEY CONCEPT ===  Private IP ranges (only usable inside a local network):    192.168.0.0 – 192.168.255.255    10.0.0.0 – 10.255.255.255   Every device on the SAME private network can normally see  and reach every other device on that same network.