Do I need a receiver for a SmartTV?

I would like to get a television on which I only want to watch Netflix, YouTube etc., so no normal television program. If I get a SmartTV, I still need a receiver to watch Netflix etc. Or the connection to the WLAN is sufficient.

In this case LAN or WLAN is sufficient.

And otherwise. SmartTV typically also has a recorder for SAT and cable.

"In SmartTV there's typically also a recorder for SAT and cable"

That's not true, only certain models are also PVR Ready, as the exception rather than the rule, and you can only record to an external hard disk or stick.