Also, you will need a hub of some kind for both Z wave and zigbee, Although sometimes devices like motorized blinds come with their own mini hub built in.
The smartthings hub includes both a zigbee radio and the Z wave radio. However, that does not mean it can work with every possible Zigbee device or every possible Z wave device. It’s just more complicated than that.
Zigbee, for example, has different “profiles.” Some work with smartthings and some don’t. Most devices using the Zigbee 3.0 profile will work with SmartThings as long as they do not require touch link commissioning and are not using the “green power“ features.
See the community FAQ for more details:
FAQ: Zigbee Application Profiles, or why not all zigbee devices work with SmartThings
With Zwave, it’s a little more complicated. Zwave defines certain functions as “basic,“ essentially on, off, and Dim. Every certified Z wave hub, like smartthings, can send a basic command to any certified Z wave device that accepts on or off commands. But other commands, including getting the battery status, sensor commands, multi button commands, etc. don’t have to be supported by the hub. So some devices with those advanced features will work with smartthings, some will work with smartthings if they have custom code, and some won’t work at all beyond on and off. These days, most of the Z wave device manufacturers will include in their product description a mention of smartthings and whether custom code is required.
So the first rule of home automation applies: “the model number matters.“