Public domain refers to the category for original creations which are not protected or bound to any owner by intellectual property laws. In this regard, a work can be defined as being in the public domain if it was not properly submitted for such protection within a sufficient period from its initial creation or presentation to the public, if the rights once accorded to it have naturally expired or if the work’s innate nature precludes it from intellectual property protections. The bounds of the public domain and the extent, if any, to which it overlaps with that of intellectual property law may be variously defined according to the context.
Shakespearean plays are commonly pointed to as a kind of original creation in the public domain, in its case due to having been created prior to the passage of modern intellectual property protection, as would specifically have taken the form of copyrights. Languages are also used as easily understandable and non-contestable examples of areas of knowledge within the public domain.
The extent to which other kinds of works and creations are placed in this category, however, can be controversial depending as much on the specific attitudes in place at the time as on any quality innate of the work itself. For example, bodies of oral literature, commonly identified as folklore, are typically viewed as being in the public domain due to their nebulous authorship, but governments have sometimes tried to obtain intellectual property protection for them on a nationwide basis.