host is a property of both the Link and the Location objects and is a string comprising of the hostname and port strings. If the port property is the default of 80, then the hostname property is the same as the host property. Assuming a link (stored in the first element of the links property) to a URL ...

http://home.newco.com/products/enquiries.htm#local?email=name@otherco.com

...the following code would display the host property of it:

Code:
document.write(document.links[0].host)

Output:
home.newco.com:80

NOTE:

Although the host property can be set at any time, it is safer to set the href property to change a link.