It's synchronous buck-boost topology, a straightforward way to up/down-convert with high efficiency. ICs are available from other manufacturers as well, but Linear has the largest portfolio.
Buckboost typically refers to the inverting type, with switches in line with both output and input. The synchronous version of a typical buckboost still can only invert the input polarity. What LT is calling a buck boost is something different, where there are four switches which at any given time function as a buck converter or a boost converter, but never as a buckboost. It's really a completely different circuit, and I wish they'd come up with a new name for it rather than improperly using buckboost... maybe bridge converter or something like that...
"Never" means, it can't invert the input voltage?
Well that's one way of putting it. I put it in terms of the canonical buckboost mechanism: power absorbed only during the on state, power delivered only during the off state. That's what defines a buckboost (or at least has for a few decades), and those ICs can never implement that behavior. Actually, the basic H bridge topology can, in a way, function as a non-inverting buckboost, but only by complementary switching of both sides of the H bridge at the same time (which none of these ICs do, but you could probably do with a standard control IC. Actually I'm surprised I've not seen that marketed before....).
The usual technical term for this is flyback converter, I think.
A flyback is a buckboost-derived converter. All the governing math is exactly the same, except with a turns ratio thrown in and maybe a switched sign convention.
Yeah, and that bothers me a bit because they're often not really interchangeable, in theory or in practice... oh well, it just means we have to pay attention to what's really going on.