Amazon and Google are about to step up their war for the future of technology (AMZN, GOOG, GOOGL)

Jeffrey Dastin/Reuters Amazon Alexa and Google Assistant are battling for supremacy in voice search. At the CES trade show, which begins in Las Vegas this week, gadget manufacturers will show off their latest products using Alexa and Assistant. Amazon has aggressively pushed Alexa everywhere, gaining dominance. Now, it's slowly but slyly turning Alexa into a big driver towards its core retail business. Google has aggressively chased after Amazon, pushing the Google Assistant into new places. But...