The complete guide – Computerworld

However you get there, once you’ve opened the Smart Lock/Extend Unlock section, you’ll be prompted to put in your PIN, pattern, or password — and you’ll then see a list of available choices:

On-body detection: Fire up this option, and your phone will remain unlocked whenever you’re holding or carrying it — so long as you’ve already unlocked it once. That way, if you unlock your phone to use it and then put it back into your bag or pocket while walking around, you won’t have to unlock it again the next time you pick it up. Anytime your phone is set down or not in motion for more than a moment, it’ll require authentication again.

Trusted places: Perhaps the most useful Google Smart Lock/Extend Unlock element, this option allows you to set specific locations — by business name, street address, or manual map placement — at which your phone will never put up a lock screen or require authentication (in theory, at least; the function can sometimes be a bit finicky and require occasional fine-tuning). You’ll obviously want to be selective about what places you choose, but configuring this to recognize somewhere like your home can be a helpful way to avoid authentication where it’s generally not needed but keep your phone secured in all other areas.