# What is the difference between a model and algorithm?

I would say that an algorithm is a private case of model because it describes how something generally works --- just mathematically.

• Questions about meaning of words are more suitable for English SE. Algorithm is not a model, it is an instruction for performing calculations, and it does not have to be private. Commented Oct 17, 2021 at 4:53
• A model is a mathematical representation of an object or phenomenon, usually a formula or a set of formulas. An algorithm is a step by step systematic (it does not require reflexion at any step) way to compute a solution to a problem. An algorithm can be based on a model, like a game of chess represented as a series of numbers, but those are two very different things. Commented Oct 17, 2021 at 4:57
• In mathematics a "model" is a collection of "objects" with their properties that satisfy a theory: natural numbers are a model of arithmetic. Commented Oct 17, 2021 at 7:51
• An algorithm is a "procedure" to solve a problem/produce a result,like the rules for addition that can be applied to a pair of natural numbers to compute their sum. Commented Oct 17, 2021 at 7:52
• Just as an observation, as well as what these words mean in mathematics, there is also a colloquial AI usage of "Model" meaning something like "a system of weighted bayesian decision networks after having been updated with training data". In this respect, sophisticated AI algorithms sometimes rely on an underlying bayesian model as part of their process of making unsupervised decisions, but the concept of Algorithm is broader than those that use Bayesian learning systems. Commented Oct 17, 2021 at 13:35