Magento configuration is spread among dozens of .xml files. So this is a reasonable question – how does Magento operate all these files and find proper settings for each particular extension?
Let’s refresh some key points of the Magento structure
• Magento is a modular system, in which functionality is located in separate modules.
• There are 3 code pools in Magento – local, community and core.
• The structure of each module includes app/code/[codePool]/Namespace/Modulename/config.xml (this file contains all basic module settings) and app/etc/modules/Namespace_Modulename.xml (this file contains information about code pool and extension activation flag).
• Global settings for Magento installation, including database connection data and admin panel address, are stored in app/etc/config.xml и app/etc/local.xml.
Refer to our previously posted certification-related articles: Magento Codepools and Magento Module Structure
If we trace the code performance starting from index.php, we’ll get the following outcome: