Why an IP is part of normal web traffic
When your browser opens a connection, packets have source and destination addressing. The website's infrastructure therefore receives network metadata necessary to return the response.
CDNs and reverse proxies complicate server logs
A site behind a trusted CDN may see the CDN connection at the origin and receive the visitor address in a trusted forwarding header. Operators must configure this carefully because arbitrary client-supplied forwarding headers should not automatically be trusted.
What the IP does not say by itself
It does not normally contain your name, exact postal address or GPS location. Sites can of course combine network metadata with accounts, cookies and other information under their own privacy practices.
How a VPN changes what the site sees
The destination usually sees the VPN exit IP. The VPN provider, however, is now part of the traffic path, which is why provider trust and policy matter.
Why websites need an IP address at all
When your browser requests a page, the server needs a return path for the response. The public IP is part of that network communication, so hiding it from the destination entirely is not compatible with a normal direct internet connection.
What changes when you use a VPN or proxy?
The destination still sees an IP address, but it is usually the address of the VPN server or proxy endpoint rather than the ordinary public IP assigned by your ISP. The network identity changes; the concept of an IP address does not disappear.