Streaming services like Hulu and Sling provide video over the internet, which can be either live or on-demand. In cases like Netflix, all of the content is on-demand - there's no live TV like news or sports whatsoever, and most local channels aren’t even an option.
Cable and satellite services, on the other hand, provide live television and video on-demand without internet - in the case of cable, through thousands of miles of cable run primarily underground, and for satellite, through signal that's beamed directly to viewers' homes. There’s no internet required and no bandwidth issues that can lead to buffering.
You may think that it's a choice of one or the other, streaming or cable/satellite, but that isn't true — with , viewers can stream thousands of hours of content, including everything on their , to their mobile devices anywhere they have internet connection. Since streaming always requires internet, cable/satellite have a leg up on them with their direct-to-home signal.