An algorithm is a set of well-defined instructions for solving a specific problem or completing a task. It is a systematic method for achieving a desired output through a finite sequence of steps. Algorithms can be implemented in software or hardware, and they are used in a wide range of applications, from sorting data to finding the shortest path in a network. The key features of an algorithm are its inputs, outputs, and the set of steps required to transform the inputs into the desired outputs. To be effective, algorithms must be correct, efficient, and easy to understand and maintain. Algorithms are the backbone of computer science, and the study of algorithms is a central part of the field.