Final answer:
The guillotine is a machine with a heavy blade sliding in grooves, invented during the French Revolution for humane beheadings, symbolizing the Reign of Terror.
Step-by-step explanation:
The machine described in the question with a heavy blade sliding vertically in grooves used for beheading people is known as a guillotine. Invented by Dr. Joseph Guillotine during the French Revolution, this device was created as a means to make executions more humane compared to the use of an axe and block. The guillotine became a symbol of the Reign of Terror, where mass beheadings occurred at places like the Place de la Concorde. Notorious figures such as Louis XVI and Marie Antoinette met their end through this method. While the guillotine's primary purpose was execution, the concept of a blade used for cutting can be found in various other contexts, such as machines used in factories or the art of Manoucher Yektai, who transformed a blade's image with inscriptions of peace.
The machine being described in the question is called a guillotine. It was an execution device used during the French Revolution in the late 18th century. The guillotine consisted of a heavy blade that would slide vertically in grooves, beheading people swiftly and efficiently. It was invented by Dr. Joseph Guillotine to improve the efficiency of executions and make them more humane.
This topic falls under the subject of History and is typically studied in High School.