Muhammad ibn Musa al-Khwarizmi was a Persian scholar who worked in 9th-century Baghdad. His work had a major influence on mathematics, especially algebra and the idea of algorithms. His book The Compendious Book on Calculation by Completion and Balancing, written around 820 CE, introduced systematic methods for solving equations. The Arabic word al-jabr in its title later became the English word algebra. Al-Khwarizmi was born around 780 CE in Khwarazm, in present-day Uzbekistan. He later worked in Baghdad at the House of Wisdom, a major center of scholarship during the Islamic Golden Age. His approach changed how mathematical problems could be solved. Instead of relying mainly on geometric figures, he described rules for manipulating equations, combining terms, and finding unknown quantities. These methods became an important part of later mathematics. Al-Khwarizmi also helped spread the Hindu-Arabic numeral system, including zero and place-value notation. His work on Indian numerals was later translated into Latin. The Latin form of his name, Algoritmi, gave rise to the word algorithm. His methods were based on clear, ordered steps: perform an operation, check a condition, and continue according to specific rules. This is closely related to the modern idea of an algorithm—a defined procedure for solving a problem. Al-Khwarizmi died around 850 CE, centuries before modern computers existed. Yet the words algebra and algorithm, derived from his work and name, remain part of mathematics and computer science today.