A printing press is a mechanical device for applying pressure to an inked surface resting upon a print medium (such as paper or cloth), thereby transferring the ink. Typically used for texts, the invention and spread of the printing press are widely regarded as the most influential event in the second millennium AD, revolutionizing the way people conceive and describe the world they live in, and ushering in the period of modernity.

The mechanical systems involved were first assembled in the Holy Roman Empire by the German Johannes Gutenberg around 1440, based on existing screw presses. Gutenberg, a goldsmith by profession, developed a complete printing system, which perfected the printing process through all its stages by adapting existing technologies to printing purposes, as well as making ground-breaking inventions of his own. His newly devised hand mould made for the first time possible the precise and rapid creation of metal movable type in large quantities, a key element in the profitability of the whole printing enterprise.

The mechanization of bookmaking led to the first mass production of books in history in assembly line-style. A single Renaissance printing press could produce 3,600 pages per workday, compared to forty by hand-printing and a few by hand-copying. Books of bestselling authors like Luther or Erasmus were sold by the hundred thousands in their life-time.

From a single point of origin, Mainz, Germany, printing spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes. In the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became so synonymous with the enterprise of printing that it lent its name to an entire new branch of media, the press. As early as 1620, the English statesman and philosopher Francis Bacon could write that typographical printing has "changed the whole face and state of things throughout the world".

From its beginnings, printing was practised also as a true art form, setting a high aesthetic and artistic standard, such as in the famous 42-line Bible. Today, incunables belong to the most prized possessions of modern libraries.

The unprecedented impact of Gutenberg-style printing on the long-term development of modern European and then world history is difficult to capture in its entirety. Attempts at analysing its manifold effects include the notion of a proper Printing Revolution and the creation of the Gutenberg Galaxy. The ready availability and affordability of the printed word to the general public boosted the democratization of knowledge and laid the material basis for the modern knowledge-based economy.

In Renaissance Europe, the arrival of mechanical movable type printing introduced the era of mass communication which permanently altered the structure of society: The relatively unrestricted circulation of information and (revolutionary) ideas transcended borders, captured the masses in the Reformation and threatened the power of political and religious authorities; the sharp increase in literacy broke the monopoly of the literate elite on education and learning and bolstered the emerging middle class. Across Europe, the increasing cultural self-awareness of its peoples led to the rise of proto-nationalism, accelerated by the flowering of the European vernacular languages to the detriment of Latin's status as lingua franca.

In the 19th century, the replacement of the hand-operated Gutenberg-style press by steam-powered rotary presses allowed printing on an industrial scale, while Western-style printing was adopted all over the world, becoming practically the sole medium for modern bulk printing.