Both Wordpress and Joomla are content management systems. But when we comparing each other then I always recommend Joomla because Joomla is specially designed for CMS ie for ecommerce development, but when we talking about Wordpress then initially it was just a blogger site used for blogging purpose, after that it redesign for CMS. So, we can say that Joomla is best because Joomla CMS have more features and it is very easy to build complex websites.