A private IP identifies a device inside a home or organization. A public IP is globally routable and is often assigned to a router or provider-facing connection in home IPv4 setups. Firewalls and provider policy can still block inbound access.
Common IPv4 private ranges
10.0.0.0/8172.16.0.0/12192.168.0.0/16
How NAT connects them
The router translates many internal connections through one public address and keeps a table so replies return to the correct device. A website normally sees the public address, not a laptop's private address.
Do not confuse privacy with secrecy
A private address is not globally routed, but devices on the same local network may still reach one another. Firewalls, guest networks and device permissions remain important.
Find each address without confusion
The operating system's network details show the local address and gateway. A public-IP service shows the internet-facing address. They may match on some IPv6 setups but usually differ on home IPv4 networks.
Do not publish router screenshots carelessly
Private addresses are not internet secrets, yet screenshots can expose Wi-Fi names, device labels, public addresses and administration details together. Redact the whole context before asking for help publicly.
IPv6 changes familiar assumptions
Devices can have globally routable IPv6 addresses while a firewall still blocks unsolicited inbound traffic. Privacy extensions may rotate interface identifiers, and multiple addresses can exist simultaneously. Do not disable the firewall because an address looks “public,” and do not assume NAT is the security boundary.
For troubleshooting, record the local address, gateway, public address, protocol and time. That context explains far more than posting an isolated screenshot.
For remote access, test reachability from a genuinely external connection. A successful check inside the same network may rely on local DNS or router loopback and does not prove that the public route works.