Movable type had been use in China and Korea centuries before Guenberg introduced his press in the mid 15th Century.
What was revolutionary was not the concept of movable type or the press, but a process of quickly making lead type. To do, Gutenberg developed a simple hand mold that was used to pour molten lead into.
This simple tool was the enabling technology for the print revolution.
Each page requires thousands of characters and to quickly print pages, there needed to be an easy way to quickly make a lot of them. By using hand molds, printers were able to make thousands of them without the need for a skilled craftsman to carve each character.
Once these presses were introduced, they began to appear throughout Europe, enabling books of all types to be economically printed and sold, spreading new ideas within the continent and beyond.