Intentional: look for a certain show/movie, e.g. the weekly episode of House MD, Lost, Friends, HBO, ... -> This is the streaming war between Netflix, HBO, Disney, ...
Casual: You turn on the tv with the aim to just browse around and relax, and get something accidentally interesting/amusing -> Youtube is king and more or less the only option here (and a bit of Nebula)
The two together is the traditional TV