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Photography is the science, art and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film.

The word 'photography' was created from the Greek roots phōtos, meaning 'light' and graphé, meaning 'representation by means of lines' – together meaning 'drawing with light.' Several people may have coined this term independently, and Hercules Florence, a French painter and inventor, used the French form (photographie), in private notes written in 1834. Johann von Maedler, a Berlin astronomer, is credited with having used it in an article published on 25th February 1839 in the German newspaper Vossische Zeitung. Despite these two early precedents, credit has traditionally been given to Sir John Herschel both for coining the word and for introducing it to the public. His uses of it in private correspondence prior to 25th February 1839, and at his Royal Society lecture on the subject in London on 14th March 1839, have long been amply documented.

Photography is the result of combining several technical discoveries. Long before the first photographs were made, Chinese philosopher Mo Di, and Greek mathematicians Aristotle and Euclid, described a pinhole camera in the fourth and fifth centuries BCE. In the sixth century CE, Byzantine mathematician Anthemius of Tralles used a type of camera obscura in his experiments; Albertus Magnus (1193–1280) discovered silver nitrate; and Georg Fabricius (1516–71) discovered silver chloride. Techniques described in the Book of Optics (an Arab text dealing with vision, light and colour, written in the tenth century CE) were also capable of producing primitive imagery.

Despite these early precedents in pin-hole and camera obscura, the first real success at reproducing images without a camera occurred when Thomas Wedgwood, from the famous family of potters, obtained copies of paintings on leather using silver salts. Since he had no way of permanently fixing those reproductions (stabilizing the image by washing out the non-exposed silver salts), they would turn completely black in the light and thus had to be kept in a dark room for viewing. Photography as a usable process (i.e. with lasting images) dates to the 1820s with the discovery of chemical photography. The first medium was photographic plate, and the first permanent photoetching was an image produced in 1822 by the French inventor Nicéphore Niépce (1765 - 1833). This image was sadly destroyed in a later attempt to make prints from it.

Because Niépce's photographs required an extremely long exposure (at least eight hours and probably several days) – he sought to improve his process, and achieved this alongside Louis Daguerre (1787 - 1851). Niépce discovered a somewhat more sensitive process that produced visually superior results, but still required a few hours of exposure in the camera. Niépce died in 1833 and Daguerre then redirected the experiments toward the light-sensitive silver halides, which Niépce had abandoned many years earlier because of his inability to make the images light-fast and permanent. Daguerre's efforts culminated in what would later be named the 'daguerreotype process'; the essential elements of which were in place in 1837. With this breakthrough, exposure time was now measured in minutes instead of hours.

Daguerre took the earliest confirmed photograph of a person in 1838 while capturing a view of a Paris street. Unlike the other pedestrian and horse-drawn traffic on the busy boulevard, one man having his boots polished stood sufficiently still throughout the approximately ten-minute exposure to be visible. Around this time, other scientists were also beginning to experiment with photographic processes - such as Hercules Florence (a Frenchman living in Brazil) who created his own process in 1832, and an English inventor, William Fox Talbot, who had created another method of making a reasonably light-fast silver process image but kept his work secret. After reading about Daguerre's invention in January 1839, Talbot published his method and set about improving on it.

At first, like other pre-daguerreotype processes, Talbot's paper-based photography typically required hours-long exposures in the camera, but in 1840 he created the 'calotype process', with exposures comparable to the daguerreotype. In both its original and calotype forms, Talbot's process, unlike Daguerre's, created a translucent negative which could be used to print multiple positive copies, the basis of most chemical photography up to the present day. Talbot's famous tiny paper negative of the Oriel window in Lacock Abbey (made in the summer of 1835), may be the oldest camera negative still in existence.

John Herschel (an English mathematician, astronomer, botanist and experimental photographer) also made many contributions to the new field. He invented the 'cyanotype process', later familiar as the 'blueprint', and was the first to use the terms 'photography', 'negative' and 'positive.' Herschel had discovered in 1819 that sodium thiosulphate was a solvent of silver halides, and in 1839 he informed Talbot (and, indirectly, Daguerre) that it could be used to 'fix' silver-halide-based photographs, and make them completely light-fast. He made the first glass negative in late-1839. Many further advances in photographic glass plates and printing were made during the rest of the nineteenth century – and glass plates were the medium of choice from the late 1850s until the general introduction of flexible plastic films during the 1890s.

Although the convenience of film greatly popularized amateur photography, early films were somewhat more expensive and of markedly lower optical quality than their glass plate equivalents, and until the late 1910s they were not available in the large formats preferred by most professional photographers. Consequently, the new medium did not immediately or completely replace the old. Because of the superior dimensional stability of glass, the use of plates for some scientific applications, such as astrophotography, continued into the 1990s, and in the niche field of laser holography it has persisted into the 2010s.

Today, photography is a booming market, and cameras have become every-day objects. There have been a number of concerns on the impact of the camera on society, not least the rise of voyeurism and passive observance, as well as our modern ability to digitally manipulate images. Further unease has been caused in regards to desensitization, with explicit images widely available, such as pornography and images of war. Modern photography and society more broadly, are still coming to terms with these issues. Photography as a science and art form has an incredibly long history, stretching back to ancient civilisations – and very excitingly, it is continuing to develop in the present day. It is hoped that the current reader enjoys this book on the subject.