Your zero inflated regression consists of two models. The zero part is usually a binomial part, such as a logit or probit model, and accounts the probability that Y is not zero. The count part is usually a model for count data (usually integers), such as a poisson or negative binomial model and only considers those observations that are not zero. When you compare the number of observations of both models, e.g. using summary(fit), you will see the difference. In sum, your zero model calculates the probability that an observations is not zero, the count model fits a model on those observations that are not zero.
Your zero inflated regression consists of two models. The zero part is usually a binomial part, such as a logit or probit model, and accounts the probability that Y is not zero. The count part is usually a model for count data (usually integers), such as a poisson or negative binomial model and only considers those observations that are not zero. When you compare the number of observations of both models, e.g. using
summary(fit)
, you will see the difference. In sum, your zero model calculates the probability that an observations is not zero, the count model fits a model on those observations that are not zero.This zero inflated regression is similar to a hurdle model. You can read more on this at Cross Validated: What is the difference between zero-inflated and hurdle models?. BTW that platform is actually better suited for this kind of merely statistical questions.