Simple theme is the default theme which comes bundled with a new installation of SilverStripe. If you download SilverStripe without this theme you can also find it on github.com to use and alter as you wish.
This theme has been kindly donated by Sara (Innovatif) as part of the SilverStripe theme competition in 2012. Themes can be tailored to the needs of a business or individual through basic HTML and CSS which every web developer is familiar with. Within a theme developers have the opportunity to build custom features like forms, image carousels and news pages using SilverStripe CMS and Framework speed up the development process.
Themes usually consist of built-in typographical styles so that content authors can choose from a predefined set font choices with set colours and size. Removing the option for content authors to chose font colours and faces produces better professionalism of the website, and makes the editing interface simpler. It also means you can later change the visual apperance or theme of your website without altering your written content.
The Simple theme is used within the tutorials on docs.silverstripe.org. Providing developers with real examples of how themes can be customized and altered to each specific need. You are welcome to customize and reuse this theme for your own personal or business use.