Backing up Data

Hi,

I got one client who happened to use a Mac O/S 10.6. She wanted to backup her data from Mac HD into her external HD every 30mins.

I'm new to Mac so I posted this question...Does Mac Desktop has built-In backup system that you can use, configure to backup your data on every specific interval period?

Or, is there a third party backup application for Mac Desktop that is quite suitable for backup job?

Appreciate your comment.