This question already has an answer here:
I'm using R to run some generalized linear models (GLM) and I want to interpret the estimates.
If I use a GLM assuming Gaussian distribution with identity link, interpretation is easy: if the estimate for factor $x$ is $y$ then an increase of 1 of factor $x$ (if all other factors remain constant) will be estimated to result in a change in the response variable by $y$ units.
Now, if I run a GLM assuming Poisson distribution with log link, in the example above, will the response variable be expected to change by $y$ units, or by $\exp(y)$ units?
note: I'm getting the estimates from summary(model object)