In how many ways we can put 12 different balls to 4 equal boxes We put 12 different balls to 4 equal boxes. How many configurations are possible?

If the boxes were distinguishable it would be simply $4^{12}$, but I do not know how to consider the fact that they are distinguishable.
When the balls are indistinguishable, you will have the following formula:

\begin{equation}
{n+k-1 \choose n}
\end{equation}

The formula counts the number of ways in which n indistinguishable balls can be distributed into k distinguishable boxes. In the following link, you can find a good explanation of the reasoning behind it. Number of ways of distributing balls into boxes
When the balls are indistinguishable, you will have the following formula:

\begin{equation}
{n+k-1 \choose n}
\end{equation}

The formula counts the number of ways in which n indistinguishable balls can be distributed into k distinguishable boxes. In the following link, you can find a good explanation of the reasoning behind it. Number of ways of distributing balls into boxes