An IP address is a unique numeric label assigned to any device connected to the internet, the actual address a request travels to even though nobody types it directly. A website has one too; DNS is the system that maps a memorable domain name onto that underlying numeric address, so a visitor types zeo.org and the request still finds its way to the right server.
There are two structural formats: IPv4, the older four-number format (like 192.168.1.1) that's technically run out of fresh addresses to assign, and IPv6, the newer, much larger format built to accommodate however many devices the internet keeps adding. Separately, an address can be static (fixed, assigned permanently to one server) or dynamic (reassigned periodically from a shared pool). For a website, a stable, dedicated IP tied consistently to the domain is generally preferable, since IP changes can occasionally cause temporary DNS resolution issues while the change propagates across the internet's various DNS caches.
