Instead of writing long lists of commands, one after another, functions allow programmers to package up functionality into smaller mini programs, known as functions or subroutines.
Take input and return an output - an example might be a function that returns the square of an input number, or as complicated as the answer to everything.
Charles Babbage is the inventor of the concept of a digital computer. Babbage was aware of the Jacquard Loom and expanded upon the punch card to invent both the Difference Engine and the Analytical Engine.
Ada Lovelace was the worlds first computer programmer, even realising that the computer could be used to make music and art.
4. Pāṇini, al-Khwarizmi, al-Jazari, Alan Turing, Tommy Flowers, Grace Hopper, Margaret Hamilton, Bugs and Hacking.
Pāṇini pioneered a grammar that incorporated metarules and recursion - making the first formal language.
Muhammad ibn Musa al-Khwarizmi formalised algebra, his name gave rise to the word algorithm and introduced the decimal system to the western world.
Ismail al-Jazari invented programmable machines, including programmable humanoid robots and an astronomical clock considered the first programmable analogue computer.
4. Pāṇini, al-Khwarizmi, al-Jazari, Alan Turing, Tommy Flowers, Grace Hopper, Margaret Hamilton, Bugs and Hacking (continued).
Alan Turing formalised the concept of the algorithm and computation in general. During the Second World War he led the team that broke German Naval codes. He went on to design one of the first stored program computers and did pioneering work in Morphogenesis, or how living things form themselves. He was prosecuted by the British Government for being gay, and committed suicide in 1954. If an system is capable of general computation it is said to be Turing complete. The Turing test is a test of machine intelligence in comparison to human intelligence.
Tommy Flowers was the engineer who built Turing's machine.
4. Pāṇini, al-Khwarizmi, al-Jazari, Alan Turing, Tommy Flowers, Grace Hopper, Margaret Hamilton, Bugs and Hacking (continued).
Grace Hopper invented the compiler for translating between human readable code and machine code.
Margaret Hamilton led the development of on-board flight software for NASAs Apollo Moon missions.