public domain- works whose intellectual property rights have been forfeited or expired
open source- generally refers to computer software code; a product or intellectual property whose design and details are accessible for the end user to repurpose or adapt
patent- exclusive rights, generally granted by a sovereign state, to a creator over the use of an invention or set of design principles for a period of time
Digital rights management (DRM) is a set of technological protection measures (TPM) rights holders place in digital material so it's value in the market is not compromised. TPM can take many forms broken down into two distinct classes, hard measures and soft measures. Hard measures are related to code that ties particular content to a particular software and/or hardware. For example, Amazon's Kindle Books have a proprietary file format (AZW) that can only be read by Amazon's Kindle software. This constitutes hard TPM. Soft TPM can often be less intrusive and limiting. It just involves a little digging to get around. Often in certain databases it is difficult, while not impossible, to copy or print material. For instance, often you need to save a PDF of a journal article on your desktop and open it with Adobe programs to be able to fully manipulate it. Viewing it in you browser (Internet Explorer, Firefox, Google Chrome, etc) from an EBSCO or ProQuest database may be limiting with regards to functionality. DRM can be placed on any type of digital file, be it audio, video, text, image, or anything else.
Intellectual property is a complex term. While is seems fairly intuitive that intellectual property involves creations of the mind, it gets much more complicated when attempting to make these creations property. A recipe or shirt design is a creation of someone's mind, yet the elements that can be deemed property are more disperse. When it comes to a t-shirt design it may seem simple to say that the graphics are creatively unique, how are things like the structure or fabric composition to be classified. Put simply, "Intellectual property (IP) refers to creations of the mind: inventions, literary and artistic works, and symbols, names, images, and designs used in commerce."
***WIPO, http://www.wipo.int/about-ip/en/ (accessed 1/24/12)