What did Johannes Gutenberg invented?

Johannes Gutenberg invented a specific kind of printing press with replaceable/moveable wooden or metal letters in 1436 and was completed in 1440. This method of printing can be credited not only for a revolution in the production of books, but also for fostering rapid development in the sciences, arts and religion through the transmission of texts.

People often say he invented the printing press, which is incorrect. Printing existed for centuries before Gutenberg. Gutenberg just developed a system that made printing easier and cheaper to do.