Permalink stands for permanent link, which is a URL (uniform resource locator) that leads to an individual post that you make in your blog. In other words, this page right here has a permanent link that you can copy and save or email or do whatever you wish with it.
For example, most people will use a permalink, if they find something on your site that interests them, and they want to let the folks over at their blog know about it. That’s when they will use what’s called a trackback to your site.
This is a permalink to my post about social bookmarking…. Click on it and see.
Let me know if this helps.