A patent examiner is a person who investigates and decides if an invention can be legally protected. In order to become a patent examiner one has to have a technical background or a background in the physical sciences, as certified by a university degree, and possibly some years of experience in an industry post. Some training in patent law is also necessary and might be provided during the first years of employment. The details depend on the country of employment.
A patent attorney (or patent agent or patent lawyer) is an attorney who is qualified to represent clients in obtaining patents, and act in all matters relevant to pattern law, such as patent disputes. A pattent attorney generally need legal training. A lawyer who has some background in the physical sciences can follow this line of work, however in many countries there are also alternative training options for people that have completed a technical course of studies, such as on-the-job training, accompanied by seminars and internships. For example, German patent attorneys have a degree in the natural sciences or engineering and have to complete additional legal training.