What is the difference between `Host` and `URL.Host` for golang `http.Request`?

Question

When developing golang http application, I use http.Request a lot. When accessing request host address, I would use req.Host, but I find that there is

Answer 1

Essentially http.Request.Host is for convenience.

r.Host is much easier to call than r.Header.Get("Host") or r.URL.Host.

Also to be noted that some routers strip the host from http.Request.URL so http.Request.Host is useful in those cases as well.

Hence it can be considered that req.Host provides the Host value even when the request header or url has been modified elsewhere.