Site name versus title

Why have a site name and title?
We have found that sites often want different text for site names and browser window titles. Menumill default themes have the site name displayed in the header or top of the page, while the site title is displayed in the title bar of the web browser.

Ok, so?
Its a best practice for designers to use these fields in theme templates, instead of hardcoding site titles etc. This way they can be updated without messing with html.

I updated the name and title, but it didn't change on my website?
If you have a customized theme or design, it may not be using these fields.