IP Addresses Explained: IPv4, IPv6, and Why Your Server Needs One

What an IP Address Actually Is

Every device connected to the internet, including the server hosting your website, has a numeric address that lets other devices find and communicate with it: its IP addressThe numeric address (like 203.0.113.10) that identifies a server on the internet.. Domain names exist entirely to give people a memorable stand-in for these numbers; underneath every domain, DNSThe Domain Name System — the internet's directory that translates domain names into the IP addresses of servers. is ultimately resolving to one of these addresses. See How Domains Work for how that translation happens.

IPv4: The Original, Limited Address Space

IPv4 addresses look like 192.0.2.10, four numbers between 0 and 255 separated by dots. This format was designed in the 1980s with room for about 4.3 billion unique addresses, a number that felt effectively unlimited at the time.

Why IPv4 Addresses Are Running Out

4.3 billion sounds large until it's measured against how many devices now connect to the internet: phones, laptops, servers, and an ever-growing list of connected devices, often several per person. The available pool of IPv4 addresses has been fully allocated by the regional registries that hand them out for years now, which is part of why techniques like shared hostingHosting where many websites run on one server and share its resources — the most affordable common option. IPs and IPv6The newer, far larger internet address format, created because IPv4 addresses are running out. exist at all.

IPv6: The Long-Term Fix

IPv6 addresses look completely different, longer strings like 2001:0db8:85a3::8a2e:0370:7334, and offer a vastly larger address space, large enough that exhaustion isn't a realistic concern. IPv6 adoption has been gradual since most existing infrastructure was built around IPv4, but most modern hosting and networks now support both side by side.

Shared IP vs. Dedicated IP Hosting

On shared hosting, the most common and cost-effective setup, many websites, including yours, share a single server IP address, with the web server software sorting incoming requests by which domain name was requested rather than by IP alone. A dedicated IP gives only your site that address, occasionally required for specific SSLThe certificate technology behind HTTPS. Modern 'SSL' is really TLS, but the name stuck. configurations, certain compliance requirements, or older software that can't share an IP. Most small business websites never need one. See choosing a shared hosting plan for more on what shared hosting includes.

How Your Domain Connects to an IP Address

The link between your domain and its server's IP address is the A record (or AAAAA DNS record that points a domain at an IPv6 address — the IPv4 equivalent for the newer address format. record for IPv6), one entry in your domain's DNS zone. When hosting is set up correctly, this record is configured automatically to point at your server; if it's ever wrong, misconfigured, or pointing at an old server after a migration, your domain simply won't reach the right place. See DNS Records Explained for exactly what that record looks like.

Do You Ever Need to Know Your Own IP Address?

Rarely for everyday site management, but it comes up in a few specific situations: confirming an A recordA DNS record that points a domain at the IPv4 address of the server hosting its website. points at the right server after a migration, setting up certain third-party integrations that ask for it directly, or troubleshooting a DNS issue where you need to verify what a domain is actually resolving to versus what it should be. Your hosting control panel typically shows your server's IP address on the account overview if you need it.