An algorithm is a step-by-step procedure or formula for solving a problem. It is a sequence of instructions that can be followed to achieve a specific goal or solve a particular issue. Algorithms are used in various fields, including mathematics, computer science, and data processing. They help simplify complex problems by breaking them down into smaller, manageable parts, making it easier to find a solution. For example, in programming, algorithms are essential for writing code that performs tasks efficiently and effectively.