The open method has a behavior similar to that of hyperlinks

[adakist]

The open method has a behavior similar to that of hyperlinks inserted with the <A> tag; however, it gives you more control over the appearance of the new window. The real benefit of using the open method, though, is that it enables you to specify the target at runtime.

[brumbino]

On the other hand, the destination of the <A> tag must be furnished at design time and can't change when the document is viewed. With the open method, you can navigate to any URL, even a user-supplied URL.