An anchor is created using the <a> tag in HTML. An anchor allows you to place a bookmark inside an HTML page. In Joomla!, you can place an anchor inside an article (for example, using the TinyMCE editor). This lets you create a link that will go directly to that point in the article. The HTML source code for an anchor looks like the following: <a name="my_anchor" title="My Anchor"></a> You can link to an anchor from within the same page using the HTML code <a href="#my_anchor" ></a> Clicking that link will take you directly to the location of the anchor tag. You can link to an anchor in a different page by appending "#" plus the anchor name to the end of the URL. In the example above, if the URL for the article was http://www.mysite.com/my_article.html, then you could link directly to the anchor in that page with the URL http://www.mysite.com/my_article.html#my_anchor.
The word "core" in Joomla! pertains to the distributed files which are needed to create and administrate a Joomla CMS powered web site. These files can be downloaded from the Joomla website at http://www.joomla.org/download.html. The Joomla "core" also contains some basic functionality to get new Joomla installations working quickly and easily. Included are the user manager, article manager, weblink manager, category manager, contact manager, and menu manager. There is also a template manager with a few basic templates to power the front-end (website/user) view, a module manager with basic modules, plugin manager with basic plugins, and a few other "out of the box" extensions to extend the functionality of a basic Joomla installation. These core's extensions should not be confused with extensions which are available for downloading from the JED (Joomla! Extension Directory). Reference: http://docs.joomla.org/Glossary
A user level on a Joomla site that by default can access only the front end. Editors have privileges to post and edit content, but no permission for publishing content.