Host

What is is.

The IP address of the computer which made the request to the web server.

What it says.

It tells you from where the request has been made. The IP address might be present in either name or number form. In either form, in consists of a host and a domain. In the name form, the counprimers/try, and possibly the physical location can be extracted, which is why the name form is more desireable.

What may cause trouble.

• Numerical addresses. The address might be in the number form (as in "192.123.2.23"). The domain name service (DNS) can be used to obtain the name by resolving the address. I might happen though that resolution is not possible at all.
• Proxies. Often requests are routed through proxy servers before they ever get to your web server. Though many individuals might access a web site, requests may seem to come from only a couple of addresses, thas is, those of the proxies. In this case, all original information on the address is lost.
• Non-country domains. Top level domains (TLDs) such as "com", "net", "org", "gov", "mil" (and now "biz", "info" and others) don't indicate the country of the address. In this case no information on location is available.
• Domain misuse. Some top level domains such "tv" (for "Tuvalu", a Pacific island state) or "to" (for "Tokelau", ditto) have been misused because the TLD suggests the address has something to do with television ("bbc.tv") or makes for nice looking adresses ("www.go.to/hawaii/"). In these cases the TLD does not really say something about the country.