If you use a script-driven platform for your site, it stores its data within a database and the more substantial the website gets, the more info it stores. For instance, if you start an e-store, the size of the database the e-commerce script employs shall increase when you add more goods. The exact same is valid for a forum script - the more users that register and the more comments they post, the bigger the database. If your sites gain popularity or you simply want to include more content, this could turn into a problem in the event that your website hosting account has limited database storage space. The specific effect of reaching the limit will be depends on the script - the website could work properly, but you may not be able to add any new info; the site can be viewed with errors; or, in the worst case scenario, the entire site may simply go offline.