If you use a script-driven platform for your website, it stores its info within a database and the larger the Internet site becomes, the more data it gathers. For instance, if you launch an Internet store, the size of the database which the e-commerce script uses shall increase when you add more products. The same is valid for a forum script - the more users that register and the more comments they publish, the larger the database. If your websites become more popular or you just want to include more content, this might become a problem in case that your web hosting account has limited database storage area. What the exact effect of geting to the limit will be depends on the script - the Internet site can work correctly, but you may not be able to include any new information; the website can be displayed with errors; or, in the most severe scenario, your whole website could simply go offline.