Alphabet will act as a holding company, which includes all of Google's various companies as well as business and search services.
Yesterday it was the last day when Google's share was traded on NASDAQ.
On Monday, Alphabet (Class A) shares and Class C Equity shares are expected to start trading on NASDAQ under the symbols "GOOGL" and "GOOG", respectively, according to the above form.
The management of all companies located under Alphabet will take on newly appointed CEOs.
Of course, we can not know what it means for the company's future as far as the end-user side is concerned. However, it is most likely that we do not see changes in how we use the products we love and use.