# The meaning of Ornstein-Uhlenbeck parameters

I am trying to understand theOrnstein-Uhlenbeck process

$dX_t = \kappa(\theta-X_t)dt + \sigma dW_t$

my question is what is the meaning of the parameters? and assuming that we know those parameters in advance what is the best way to exploit it?

$\theta$ is the "mean" for this process. If $X_t > \theta \implies (\theta - X_t) < 0$, which means that the drift for the process is negative and tends towards $\theta$. The opposite case can be made for $X_t < \theta$ ; the process will have positive drift when $X_t$ is below $\theta$.
Therefore we can consider $\kappa$ to be the "speed" of mean reversion, scaling the distance between $X_t$ and $\theta$ appropriately to match whatever is being modeled.
$\sigma dW_t$ is your standard Wiener process scaled by volatility $\sigma$.
In plain English you can interpret the differentials as a process that reverts to a mean, $\theta$, with speed, $\kappa$, and volatility, $\sigma$.