The concept of television "flow" is one that has gained great currency within academic television studies. Basically, flow is the idea that TV is constituted by a constant flow of images and sounds that take the form of different televisual elements (such as segments of programs, interstitial items such as promos and stations IDs, and commercials). It is this flow, much more than any programs or specific type of program, that characterizes television as a medium.
This clip is an example of televisual flow, here in a segment from NBC from August of 1983. The segment begins with the opening of "NBC News Digest," a sample of the kind of interstitial news updates that networks used to offer in the days prior to 24-hour cable news. (Featured news stories include an upcoming space shuttle launch and the military conflict in Beirut, Lebanon.) The flow also includes commercials for Airborne Express, Pepsi Free, and Burger King, a brief local news promo, and, at its very end, the opening title for an NBC movie.
(Length: 2 mins. 34 secs.; video source: YouTube)