History of computer

The first use of word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle 20th century. From the end of the 19th century the word began to take on its more familiar meaning a machine that carries out computations.

                    Charles Babbage developed the first analytical engine in 1812. This machine had the concept of modern computer namely memory, arithmetic unit and capacity to handle stored programme. But this machine could not be put into practical applications due to technologies limitations that time.
                       The history of modern computer begins with two separate technologies, automated calculation and programmability, but no single device can be identified as the earliest computer, partly because of the inconsistent application of them. A few devices are worth successful and survived for centuries until the advent of the electronic calculator, like the Sumerian abacus, design around 2500 BC of which a descendant won a speed competition against a modern desk calculating machine in japan in 1946, the slide rules, invented in the 1620s, which were carried on five Apollo space missions, including to the moon and arguably the astrolabe and the Antikythera mechanismn an ancient astronomical computer built by the Greeks around 80 BC. The Greek mathematician Hero of Alexandria (c. 10-70 AD) built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums that might be considered to be a means of deciding which parts of the mechanism performed which actions and when. This is the essence of programmability.