Crash course on patents
A patent is, briefly speaking, the exclusive right to an invention. An invention is generally considered to be a man-made, technical creation, although recently also "inventions" in the field of computer software and methods of doing business are considered patentable.
Patent rights to an invention are obtained through an examination procedure at a national or international patent office. This examination typically consists of two steps: first, a literature search is performed to determine what was known at the filing date of the patent application, and second, an Examiner considers the documents found in the literature search and determines whether the invention is patentable in light of these documents. If this is the case, the applicant receives a patent on his invention. He can then exclude others from using the invention in the country in which the patent was granted.
The procedures for obtaining a patent, and the subsequent determination of the scope and validity of a patent once granted, are fairly complex. Much depends on the specific facts of the case and on the law in the country in which a patent is applied for. So, the below advice should be regarded as a general introduction only.