Samsung acquired Viv Labs, started by the creators of Apple's Siri. They're working with Samsung's new Bixby artificial intelligence team, but they haven't built anything in the Bixby you'll see on the Galaxy S8. Bixby can be called up through a dedicated button on the left side of the smartphone, or by speaking "Bixby."
The AI can be used for standard things, like asking the weather or sports scores, or even for identifying a bottle of wine or a book through the Galaxy S8's camera. Bixby can also be used to help place phone calls, manage appointments, present relevant information based on the time of day and more. Is it better than Siri or Google Assistant? We'll need to test it more to find out, but the good news is the latter still comes pre-installed.