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The Analytical Engine was never built in Babbage's lifetime. What he had, and what I translated from Menabrea's Italian paper in 1843 with my own notes appended, was the complete logical design for a general-purpose computing machine: an input device (punched cards, borrowed from Jacquard), a store for numbers, a mill for arithmetic operations, and an output device.

My notes were longer than the paper I was translating. In Note G, I described an algorithm for computing Bernoulli numbers — a sequence of steps for the machine to follow that would produce a mathematical result without any human intervention beyond setting up the initial conditions. This is what is now called a program.

Babbage had thought of the machine as a calculator. I thought of it as something that could manipulate any symbols according to any rules — music, text, logic, not only numbers. He was building an adding machine. I was describing a computer. The difference is not small.