The default Joomla! layouts for menu items which use the Category Blog Layout. Blog format presents some or all of the articles in a particular category or sub-category. The standard presentation usually includes an article’s title as a link, followed by some introductory text and a Read More link.

The visible graphical interface features of an application are sometimes referred to as chrome. See Applying custom module chrome for information about how to modify the look of modules (in other words, the module "chrome").

Reference: http://docs.joomla.org/Glossary