What Is an IP Address?

How IP addresses work

Every device on a network uses at least one IP address. When you visit a website, your computer sends a request to the server's address, and the server sends the page back to yours. Neither side could find the other without one.

Addresses are handed out in a chain. IANA (the Internet Assigned Numbers Authority) allocates large blocks to 5 regional registries, which pass them to internet service providers (ISPs). Your ISP assigns a public address to your connection, and your router uses DHCP (Dynamic Host Configuration Protocol) to give each device in your home a local address automatically. You almost never have to set one by hand.

IPv4 vs. IPv6

The difference is capacity. IPv4 is a 32-bit format with room for about 4.3 billion addresses. IPv6 is a 128-bit format with room for about 340 undecillion, a 39-digit number.

• IPv4: the original Internet Protocol version, specified in RFC 791 in September 1981 and deployed across the ARPANET in 1983. Written as four numbers from 0 to 255, for example 192.0.2.146.
• IPv6: its successor, an Internet Standard since 2017. Written as eight groups of hexadecimal digits, for example 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

IPv6 exists because the internet outgrew IPv4: IANA allocated the last of its unassigned IPv4 blocks on February 3, 2011. The replacement is now past the halfway mark. On March 28, 2026, native IPv6 connections to Google crossed 50% for the first time (50.1%, per Google adoption data reported by the Internet Society). For a deeper look at what the change means for your site, read our guide to IPv4 vs. IPv6.

Types of IP addresses

Two splits matter in practice: public vs. private, and static vs. dynamic.

• Public: the internet-facing address your ISP assigns to your connection. It's what websites see when you visit them.
• Private: the local addresses your router hands out, drawn from reserved ranges like 192.168.x.x and 10.x.x.x. The same private addresses repeat in every home, so an IP address is only guaranteed unique within its own network.
• Dynamic: an address that changes periodically. It's the default from your ISP, and it's fine for browsing, streaming, and email.
• Static: an address that never changes. It's the simplest choice when DNS records, allowlists, or remote access must keep pointing at the same endpoint.

Public addresses are shared more often than not. In a typical home IPv4 setup, your router uses NAT (network address translation) to let every device share the connection's one public address, and some ISPs add carrier-grade NAT, which puts several households behind a single public IPv4 address. IPv6 has no such shortage, so IPv6 devices commonly hold their own globally routable address alongside a local one.

At home, you almost certainly have a dynamic public address. Servers usually sit on static addresses, but a fixed address isn't strictly required: dynamic DNS can update a domain's records each time the address changes, at the cost of extra setup and brief interruptions after each change. One special case to know: 127.0.0.1 is reserved for localhost, the address every computer uses to reach itself.

IP addresses, domain names, and your website

You rarely type an IP address yourself, because the Domain Name System (DNS) translates memorable, human-friendly domain names into them. When someone enters your domain, nameservers answer the lookup with your site's A record, the DNS record that maps a name to an IPv4 address; an AAAA record does the same job for IPv6.

To see where your own site lives, open the Manage Websites page in your DreamHost panel and check the site's DNS settings: the A record listed there is your website's IPv4 address, and any AAAA record is its IPv6 one.