For example, if you tell it you fancy a coffee, the Assistant will automatically find every restaurant near your current location and can mark them out on a map; it will even guide you straight to the door with voice commands.
In the same way, if you ask what this virtual assistant can do for you, it will tell you that it is capable of, for example, updating your Facebook status with whatever message you have in mind, tell you what the weather´s like outside, or simply find some information on Wikipedia for you.
The customization options are actually somewhat limited and just allow you to choose between two different assistant images (although you can also choose a simple microphone), and choose whether you want it on a neutral background or on your own 'wallpaper'.
Assistant is a useful tool for any user who isn´t a big fan of Siri, as it provides a great source of information, a calendar, and more. It will always be available on your mobile phone screen, and just in case there is a lot of background noise, you can still write whatever you want.