In order to provide distinction between Asterisk and Asterisk SCF, the following analogy is provided.
Kit Car vs. Parts
Asterisk is a kit car. It comes with all the pieces you need to assemble your own car. It's extremely flexible, so you can assemble it into a sports car, a sedan, a dune buggy, a mini-van; or, with some significant effort, a bus.
If Asterisk is a kit car, Asterisk SCF is a collection of premium parts that can be assembled into virtually any kind of transportation. With Asterisk SCF you can build not only cars and buses, but also trains, cruise ships and moon rockets.
The "parts" that come with Asterisk SCF each perform one specific function and can operate independently of any other part. This is quite different from Asterisk, which requires all the parts be built into the same vehicle and operate as one. This starts to make sense if you think about a moving vehicle. It would be very hard to expand a two-seat car into a sedan or a bus while its moving. That is because all the parts are welded together, and the alteration would require cutting the car in half and welding in a new row of seats – not something you want to do on the open highway.
A vehicle built from Asterisk SCF is more like a train than a car. Adding capacity does not require major surgery. You simply link in more cars and voila: you have more capacity.