Quick answer: A static IP address stays the same every time you connect; a dynamic IP address is reassigned periodically by your ISP from a shared pool. Most home connections are dynamic by default.
Why most home connections are dynamic
Dynamic addressing lets an ISP reuse a limited pool of IPv4 addresses across many customers, since not everyone is online using an address at the same moment.
When a static IP is used
Businesses, servers and some self-hosted setups often request a static IP so the address never changes — useful for remote access, port forwarding or running a mail server.
Check your own address
Run IP Lookup now, then again after reconnecting your router. If the address changes, your connection is dynamic. Read more in What Is NAT? and our guide on why your IP address changes.
Want to see this in practice? Check your own connection's IP, location and ISP.
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