# What is logistic regression? When do we need to use it?

Logistic regression is a Machine Learning algorithm that is used for binary classification. You should use logistic regression when your Y variable takes only two values, e.g. True and False, “spam” and “not spam”, “churn” and “not churn” and so on. The variable is said to be a “binary” or “dichotomous”.

## Is logistic regression a linear model?

Yes, Logistic Regression is considered a generalized linear model because the outcome always depends on the sum of the inputs and parameters. Or in other words, the output cannot depend on the product (or quotient, etc.) of its parameters.