Pamela Fox:

What is an algorithm? It’s a sequence of steps that you follow to solve a problem. In everyday life, you might have an algorithm for hanging up your laundry, efficiently going through a shopping list, or finding an empty parking space in a lot. In computer science, an algorithm is a sequence of instructions that a computer program follows. Algorithms form the basis of the most interesting and important programs we use, such as the algorithm that Google uses to calculate driving directions, or the algorithm that Facebook uses to automatically tag you in a photo.

Because algorithms are so important to computer science, they are a core part of a computer science curriculum. The AP CS A class teaches object-oriented programming with algorithms, every college CS student will have at least one algorithms class and encounter algorithms everywhere, and every software engineer interviewing for a job will review algorithms while they’re prepping for an interview.