Open source hardware means that people:
How open source has changed the hardware environment
While open source software is a relatively well-known concept by comparisons, the idea of open source hardware isn’t quite as publicized. In fact, few people are aware that there are quite a few organizations offering open source hardware, which meansthey have made all information pertaining to their products freely available, including designs and schematics, bill of materials information, and printed circuit board layout data. Generally, open source software is used in the original design, which provides evenmore benefits.
The driving ideology behind open source hardware is that anyone should have the freedom to:
• Use the device for any purpose.
• Study how it works and make any changes.
• Redistribute the design of the device and the device itself.
• Enhance the design as well as the device and make those improvements freely available to the public so all can benefit.
(http://opensource.com/life/15/2/open-source-hardware-future-tech)