Alphabet is the parent corporation of Google and became Google's publicly traded parent through a 2015 restructuring.
The restructuring separated Google's core internet businesses from other projects, including research and technology ventures. Google became a subsidiary of Alphabet, while Alphabet became the listed holding company whose shares investors trade.
Alphabet retained Google's original stock-market identity through the same share classes and ticker symbols. Its major businesses include Google Search, YouTube, Android, Google Cloud, and advertising services.
People sometimes call the entire company Google, but the legal corporate parent is Alphabet Inc. That distinction matters when discussing market capitalization, because Alphabet's market value represents the combined public company rather than Google Search alone.