Public vs Private IP
Every connected device has an IP address, but the one you see in your router is often not the one websites see. That difference comes down to public versus private IPs.
Public IP
A public IP is assigned by your ISP, is unique across the internet, and is directly reachable. Websites and servers typically see your public IP. Because IPv4 is scarce, public IPs are a limited resource.
Private IP
A private IP is used only within a local network (home or office) and never appears on the public internet. Your router uses NAT (Network Address Translation) to let many devices share a single public IP. That is why a household with a dozen devices may receive only one public address from the ISP.
Common Private Ranges
10.0.0.0/8172.16.0.0/12192.168.0.0/16(most common on home routers)
How to Tell Which You Have
If IP Lookup shows an address like 192.168.x.x or 10.x.x.x, that is a private IP (meaning the site saw an address behind a proxy). Normally it shows your public IP. In the IPv6 era every device can have a public address, greatly reducing the need for NAT.