Algorithms are well-defined procedures to solve problems and were first developed by the Persian mathematician Al-Khwārizmī in the 9th century. In the 18th century, algorithms evolved into the form known today. Ada Lovelace wrote the first algorithm for a computer in 1842 and is considered the first computer programmer. Alan Turing introduced the concept of a Turing machine in 1936 to model how a computer works. For a machine to understand and implement an algorithm, it must be unambiguous, executable, and finite. Examples demonstrate algorithms as a series of conditional IF-THEN-ELSE statements to solve problems like printing a document.