Data Limitations on Wifi?

I was told by a customer service rep. this morning that there is a data plan with data limits on wifi internet services. Are there data limitations on home internet now? This sounds more like something that would be associated with mobile plans. When I try to search up what these limits are, I can only find information regarding mobile data plans. But to be clear, my question does NOT pertain to mobile plans since Comcast Xfinity is not my mobile provider.