The article is dedicated to the basic Magento architecture as well as its comparison with both Magento versions. As for Magento 1 structure, all relevant description you can find in the article Magento Module Structure. As for Magento 2 structure, it is shown in the picture below.
Cron job is the main way to run repeated tasks. It’s used in Magento for such tasks as indexing, email processing, currency rate update. (more…)