Complex sentence: One is called the "weak" law and the other the "strong" law, in reference to two to different modes of convergence of the cumulative sample means to the expected value; in particular, as explained below, the strong form implies the weak.
Split into simpler sentences: One is called the "weak" law and the other the "strong" law. These forms do not describe different laws but instead refer to different modes of convergence of the cumulative sample means to the expected value, and the strong form implies the weak.