In the beginning, a design was implemented for a mission critical data base, a server to run it on, and a scripting language to access it on the internet, all running together on a linux operating system. Apache is the server, MySQL is that date base, and PHP is the scripting language (LAMP stack). All four are free, They are also the choice for most web sights, including this one.
MySQL doesn't have all the features of Oracle's premium data base. It specializes in speed, reliability, and accuracy. What it does it does as well as any data base out there. Depending on the size of your company, premium data bases can cost hundreds of thousands of dollars. "Free" is a substantial feature. It can be downloaded at http://www.mysql.com/
PHP and Java Script (not Java) are both scripting languages. Java Script runs on end user computers, PHP runs on the server and sends output to the end user. They each have features the other doesn't. PHP is open source and can be downloaded for free at http://www.php.net/
The phone book and portfolio are PHP script files accessing MySQL data bases. The programs are pretty impressive but they contain sensitive data and I had to secure them. As this web sight is also my resume I can create temporary passwords to demonstrate.