Blocks are components of simplest construction. They are used for displaying information on the sidebars of web site.
There are 5 main positions for blocks:
- Top
- Right
- Bottom
- Left
- Floating
First 4 positions are obvious, they mean displaying of block around main content. Last position is really floating, it is used to insert block inside content with the help of inserting into raw html content.
Block may be presented by php files or just HTML specified in administration area of web site. In case of php file - it will be included, output will be used as block content. Obviously, file may contain only HTML without any php code.
All php blocks are located in directory blocks with names block.{block_name}.php. Usually blocks are used to display some information of modules, for example last news.