In comparison with a static HTML site where all content is on the actual website pages, any script-driven Internet site stores all of its data in a database. Just a few examples of such Internet sites are a WordPress blog or an OpenCart electronic commerce portal - in both cases, product or service listings, prices, blog posts, user reviews etc are collected in the database and not inside the actual script files. The more the info you add, the larger the database becomes and if your web hosting package has some limit for the maximum size a database could have, your website may not work correctly after you reach that limit. The results can vary from being unable to include new information to improperly working Internet site or even the website displaying nothing but error messages and not being available at all.
