Dynamic websites with databases and administrative interface getting up frequently used from web business. The databases aren't an extra or especial effect. They serve for saving various data, if you use databases, you have possibility updating contents of your website every day, to collect information for your visitors. The all information published in your website saved in database and you can easy manage her.
All bigger websites in internet use services of databases - online shops, web forums, classified ad-board, online tests, top sites, dating websites, social networks and so on.