What is the reason for using the page's header as a link to itself?

I noticed many web sites use

<h1><a href="/subdir/somepage/">bla bla</a></h1>

in the page example.com/subdir/somepage/

Why do they do that? SEO? Compliance to some standard I don't know? Does it really help users in any way?

EDIT: after many of the answers obviously misunderstood me. I'm not talking about a link to the homepage of the site. I'm talking about a question page in SO using the question's text in H2 element (see that above?) to link to the same page开发者_JAVA百科.

if I want to cut and paste a page link, it's one operation (in Firefox) to right-click the page title and select "Copy Link Location." Swiping (or doing select-all) on the URL and then hitting control-C is two operations.

I don't think the link is particularly useful, except in two cases:

• If for some reason, you cleared your location bar (or overwrote it with something else), you still have access to the link to the page,
• Similarly, if the location bar is not visible, you can still get the link to the current page easily.

I am not sure if the reasons are very compelling, though.

Most probably, some smart php (or perl) script generates some standard heading content for all the pages in the site. That's why it may suddenly contain the link to itself.
Also it helps to keep pagerank intact.

I find this feature really useful. It means that no matter where I am on the website, I can just click the website's title to take me to the home page.

Since urls from other sites often deep link, I might read an article and then decide to take a look at the rest of the site - is it interesting, does it look legitimate, etc.

Please implement it in your sites!

Just take a look at some inexperienced user - they click it whenever they're lost. And to be honest I started using it myself, as a quickest bookmark that you doesn't even have to create.

From design/usability point of view, such link is filled with semantical meaning: "look, it's me!"

Ofri, in your example, I believe alemjerus and Tomasz Zielinski have covered it for you. It's a link to the home page of the site that is automatically built by the server. It's really common and I tend to use it frequently for blogs in particular.

Think of your favorite blog or community web site that updates often. You generally bookmark or browse to the address of the home page, and you're presented with the most recent content. If you refresh the page, say, an hour or a day later, you may see different content.

Now suppose you come across one particularly inspired entry during your lunch break, and you email the link to your friend who always answers questions on Stack Overflow between noon and 1PM. By the time your friend reads your email, the content will have changed.

If only there were some way to email a link to the specific entry you want to share....