An algorithm is a set of precise, ordered steps designed to solve a specific problem or accomplish a particular task. Algorithms are foundational in computing and software development, guiding how data is processed to produce a desired outcome.

Each algorithm takes an input, processes it through a series of defined steps, and delivers an output. For example, search algorithms in a database might take a query as input, search through records, and return relevant results as output. Algorithms vary in complexity, from simple arithmetic functions to complex machine-learning algorithms that analyze large data sets.

Key features of an algorithm include definiteness (clear, unambiguous instructions), finiteness (it completes in a finite number of steps), and effectiveness (its steps are simple enough to be performed by a human or a computer). Well-designed algorithms optimize performance, improving speed, accuracy, and resource efficiency.

For instance, sorting algorithms like quicksort or mergesort organize data efficiently, impacting processing time in large applications. Search engines use complex algorithms to sift through massive data to provide accurate results. In fields like cryptography, encryption algorithms protect sensitive data, while in artificial intelligence, learning algorithms help systems adapt and improve over time.

In essence, algorithms are essential building blocks in computing, helping automate tasks, solve problems, and drive decision-making across a wide array of applications.