Say we have a set G, with cardinality g. Then the cardinality of the power set of G is denoted as \(\displaystyle 2^{g}\), which you can verify for finite cardinals. The cardinality of the reals is equal to the cardinality of the power set of the natural numbers, ie. \(\displaystyle 2^{ \aleph _0 }\). There may be some higher meaning to this with infinite cardinals but if you like you can simply call the cardinality of the reals \(\displaystyle \aleph _1\).