Professionally, an architect's decisions affect public safety, and thus an architect must undergo specialized training consisting of advanced education and a practicum (or internship) for practical experience to earn a license to practice architecture. Practical, technical, and academic requirements for becoming an architect vary by jurisdiction.
Throughout ancient and medieval history, most of the architectural design and construction was carried out by artisans—such as stone masons and carpenters, rising to the role of master builder. Until modern times, there was no clear distinction between architect and engineer. In Europe, the titles architect and engineer were primarily geographical variations that referred to the same person, often used interchangeably.
It is suggested that various developments in technology and mathematics allowed the development of the professional 'gentleman' architect, separate from the hands-on craftsman. Paper was not used in Europe for drawing until the 15th century but became increasingly available after 1500. Pencils were used more often for drawing by 1600. The availability of both allowed pre-construction drawings to be made by professionals. Concurrently, the introduction of linear perspective and innovations such as the use of different projections to describe a three-dimensional building in two dimensions, together with an increased understanding of dimensional accuracy, helped building designers communicate their ideas. However, the development was gradual. Until the 18th-century, buildings continued to be designed and set out by craftsmen with the exception of high-status projects.
In most developed countries, only qualified people with appropriate license, certification, or registration with a relevant body, often governmental, may legally practice architecture. Such licensure usually requires an accredited university degree, successful completion of exams, and a training period. The use of terms and titles and the representation of oneself as an architect is restricted to licensed individuals by law, although in general, derivatives such as architectural designer are often not legally protected.
To practice architecture implies the ability to practice independently of supervision. The term building design professional (or Design professional), by contrast, is a much broader term that includes professionals who practice independently under an alternate profession, such as engineering professionals, or those who assist in the practice architecture under the supervision of a licensed architect, such as architectural technologists and intern architects. In many places, independent, non-licensed individuals may perform design services outside the professional restrictions, such design houses and other smaller structures.