Careta offers automaticly a little set of shortcodes that you can use to emphasize some portions of your text.
A lot of Plugins give this support for WordPress, but the Theme have the vantage to bring everything that you need in a single file. without need to install thirdy files.
You can use the shortcodes with this sintax:
[alert] some text [/alert] [info] some text [/info] [error] some text [/error]
On use it, the page/post show a specific style for the text into a box: