The history of computers goes back over 200 years. At first theorized by mathematicians and entrepreneurs, during the 19th century mechanical calculating machines were designed and built to solve the increasingly complex number-crunching challenges. The advancement of technology enabled ever more-complex computers by the early 20th century, and computers became larger and more powerful.

Today, computers are almost unrecognizable from designs of the 19th century, such as Charles Babbage’s Analytical Engine — or even from the huge computers of the 20th century that occupied whole rooms, such as the Electronic Numerical Integrator and Calculator.