I just wanted you all to know that everything works just like it is supposed to work. I have seen all the posts where this or that doesn’t work but I am a rebel. I have Sengled bulbs, Samsung outlets and open close sensors, and Ecolink motion sensors and a GE switch. The Ecolink and GE switch are Z wave and the rest of the stuff is Zigbee. I decided to not go WIFI with the accessories so I wouldn’t overload the WIFI system. I have lights come on and off when I enter rooms, and when I leave home the lights go off and when I return, they come back on. GREAT. Plus, I have Alexa in the mix to control the Nest Thermostat and lighting.
What is really neat, when I had trouble this week with the internet dropping out, the motion sensors and associated lights still worked. I didn’t do anything special in the setup but they worked together. I am really enjoying my journey with Smart stuff and I will continue to add more accessories in the future.
Kaplock.
Welcome but becareful! This is how they get you and before you know it, you’re going to need this 
There are a lot of things you can be addicted to, but Smart stuff seems pretty tame compared to the others.
Hi I’m @Gogorichie and I’m an addict too. Like you I bought my smartthings hub last December everything worked just like it should and one year later I’m sitting with about 22 devices connected. Welcome to the club!!!
Newbie here too, I just left LOWES (iris) and all of my devices are compatible with ST… Since I won a contest for IRIS and I was in one of their commercials all of my devices were free… 
I don’t think we have much documentation that explains what functions if the internet is out vs not but to clear up some of the mystery for “local” execution the following criteria needs to be met:
- Hub firmware 18.x + (hub v2 or adt panel)
- Selected devices able to “Run Locally”:
https://community.smartthings.com/t/faq-confirmed-local-processing-working-device-handlers - Select smart app able to "Run Locally"
The apps are:
Smart Lighting and the Smart Home Monitor “behavior” apps which are:
“Alert with Lights”, “Alert with Sirens”, “Close Valves” and “Unlock Doors”. The actions selected in those apps will still execute if the internet is out.
Just login to: https://account.smartthings.com with your SmartThings app credentials and go to the “Devices” page to see which devices can run locally. To see the apps, go to the Locations tab, then select your location (or you will automatically be redirected to the right one if you only have one), then click the “List SmartApps” link at the bottom and you will see a list of all your installed apps and if they are local or in the cloud.
Now that you have all this info that you didnt ask for… Welcome to ST and the community!! 