Local Networks vs the Internet
Not all networks are created equal. The network in your home and the global internet are both networks, but they differ dramatically in scope, privacy, and how they're managed. Understanding this distinction helps you grasp how your devices connect to the wider world.
Local Networks: Your Private Space
A local area network (LAN) connects devices in a limited physical space — your home, an office, a school building. When your laptop talks to your printer or your phone streams to your smart TV, that traffic stays on your local network.
Local networks are typically:
- Private — devices outside can't directly access them
- Fast — short distances mean low latency
- Controlled — you (or your organization) manage the equipment
Your home router creates a local network. Every device connected to your Wi-Fi or plugged into your router joins this private network and can communicate with other devices on it.
The Internet: Network of Networks
The internet isn't a single network — it's millions of networks connected together. Your home network connects to your internet service provider's (ISP) network, which connects to larger regional networks, which connect to global backbone networks spanning continents.
This interconnection is what makes the internet powerful. A device on your local network can reach a server on the other side of the world because the networks in between have agreed to pass traffic along.
How They Connect
Your local network meets the internet at your router. The router has two roles:
- Internally — it manages your local network, assigning addresses to your devices
- Externally — it connects to your ISP and represents your entire home as a single point on the internet
When you request a webpage, your device sends the request to your router. The router forwards it to your ISP, which routes it through the internet to the destination server. The response travels back along a similar path.
The Neighborhood Analogy
Think of your local network as streets within your neighborhood. Traffic flows freely between houses (devices) on those streets. The internet is like the highway system connecting all neighborhoods everywhere.
To leave your neighborhood, you go through an on-ramp (your router). To reach a specific destination, your traffic travels highways managed by different authorities (ISPs and backbone providers) until it arrives.
Why the Distinction Matters
Understanding local vs internet traffic helps with:
- Security — local network traffic is private; internet traffic passes through many hands
- Speed — local transfers are fast; internet speed depends on your connection
- Troubleshooting — knowing where a problem occurs (local or internet) guides the fix
Your devices live on your local network but reach the world through the internet.