CGI is Comman Gateway Interface. Most of the CGI scripts written in Perl are storing the data in flat text files (ASCII files). Since CGI written in Perl are good in extracting in data from text files. Since the security given by UNIX is good enough to prevent users to access this files. But if you need an external database to store the data you can use mySQL. You need to setup the mySQL database running along with your web server first.