Some locks integrate with other connected home devices, like Wireless smoke sensor,
and services, like Amazon Alexa, Apple HomeKit, Google Assistant, and If This Then That (IFTTT).
For example, you can have your doors unlock when a smoke or CO alarm is triggered,
or have certain smart lights turn on when a door is unlocked.
Depending on your home automation setup, you can even pair your lock with a video doorbell,
so you can see who is at the door before you unlock it,
or have an indoor security camera begin recording when a door is unlocked.
Just remember: The more features you get, the more you can typically expect to spend.