– webroot [magento project root directory]

 – app [contains code pools, design, configuration, localization and Mage.php files]

– code [contains the code files]

– community [third party modules]

– core [magento core modules]

– local [local modules]

– design [contains modules templates and layout files]

– adminhtml [contains the templates and layout of admin area]

– frontend [contains the templates and layout of front area]

– install [contains installation files]

– etc [contains the system and modules configuration files]

– local.xml
– config.xml
– modules [module configuration files]

– locale [contains the localization files]

– Mage.php [main entry point of magento framework]

– js [javascript library files]

– lib [external libraries include varien, zend framework, etc.]

– media [contains product, cms images, etc]

– skin [contains the css and js file based on the theme]

– var [contains the system generated directories like cache, report, sessions etc]

– cron.sh [cron to make task automatically]

– index.php [main entry point for php application]