What Are Blocks in Magento?

In the Magento architecture, a "Block" is one of the first class elements in the structure of Magento layouts. Every page in Magento is decorated by the "Layouts" file and the content is filled up by the "Blocks" of the different modules. Magento blocks are a really powerful and flexible way to plug­ your content into the already existing layouts. On the other hand, you could also use layout XML files to easily remove or Reposition any existing blocks.

Structural Blocks

We could say that "Structural Blocks" are the containers holding the "Content Blocks". Structural blocks themselves don't have any actual content to display, but they in turn display the content blocks at the end. As the name suggests, they're used to structure the content of the whole page.
For example, "Header", "Footer", "Left" and "Right" are structural blocks in Magento. "Content blocks" are assigned to the different structural positions of the layout of the Magento page, which in turn displays the actual content of the content blocks.

Content Blocks

"Content Blocks" are the real fire power, generating the actual content for the display. As we've just discussed in the previous section, you need to assign the content block to one of the structural blocks for the front­-end display. There are some other ways which allow us to insert the content blocks using short codes, but we'll see more on that later.
Content blocks can be of any form, from a simple static content block to a list of the most recent products on the home page! In fact, the majority of the content is generated by the content blocks spread all over the different modules in Magento.

Custom Block Development

We're going to develop a very basic custom Magento module for the development of our custom block. Our custom block will be a simple block displaying the most recent products available in the store.
I assume that you're familiar with the basic structure and conventions of the Magento module files. Now, let's see the file structure we'll need to implement for our custom block.

• app/etc/modules/Envato_All.xml: It's a file used to enable our custom module.
• app/code/local/Envato/Recentproducts/etc/config.xml: It's a module configuration file.
• app/code/local/Envato/Recentproducts/Model/Recentproducts.php: It's a model file which provides the array of most recent products.
• app/code/local/Envato/Recentproducts/Block/Recentproducts.php: It's the main block file for our custom block.
• app/design/frontend/default/default/template/recentproducts/recentproducts.phtml: It's a template file which contains the XHTML-related stuff.