  We compute the growth fluctuations in equilibrium of a wide class of
deposition models. These models also serve as general frame to several
nearest-neighbor particle jump processes, e.g. the simple exclusion or the zero
range process, where our result turns to current fluctuations of the particles.
We use martingale technique and coupling methods to show that, rescaled by
time, the variance of the growth as seen by a deterministic moving observer has
the form |V-C|*D, where V and C is the speed of the observer and the second
class particle, respectively, and D is a constant connected to the equilibrium
distribution of the model. Our main result is a generalization of Ferrari and
Fontes' result for simple exclusion process. Law of large numbers and central
limit theorem are also proven. We need some properties of the motion of the
second class particle, which are known for simple exclusion and are partly
known for zero range processes, and which are proven here for a type of
deposition models and also for a type of zero range processes.

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