The Wolfram Language is the common language denominator for any current and future product that uses it. This product can be Mathematica (the desktop product), or webMathematica or gridMathematica to name a few currently shipping products, but it can also be a future product (like:
Wolfram Cloud ), or a product running an embedded version of the Wolfram Language (with no frontend or perhaps not even an interactive kernel session), or an app on iOS based on the Wolfram Language.