Now a day face lock is seen in apple iPhone X, from now onwards you can set your android (MOTO,lenovo, etc...) phone with faceID. To set up this feature perform some of these steps given below.

1. Go to settings
2. Swipe down and select security
3. Then select SMART LOCK
4. If you already set password enter it.
5. Select trusted face, then your front camera will on then show your face properly.

After the setup is completed you can turn of the screen and click the power button. When the lock screen appears show your face, after that  simply slide up phone will unlock.