Borel probability measure vs Probability measure

Question

Is there a difference between these two terminologies?

1. space of all Borel probability measure on $\mathbb R^n$ or some complete, separable metric space.

2. space of all Probability measure on $\mathbb R^n$ or some complete, separable metric space.

In other words, what would be differences in the definitions of a Borel probability measure and a probability measure on the above mentioned spaces.

Thanks for explaining to me.

Answer 1

In 2) the sigma-algebra is not specified.

In 1) the sigma-algebra is the sigma-algebra of all Borel sets, the one generated by open sets.