SpaceX's raptor engine

An explanation for the meaning of the term "full flow staged combustion cycle".  Quite a mouthful there.

Just say "new design" that hasn't been on a flight yet.  In other words, it is breaking new ground.  It isn't really a new design.  It is simply a design that hasn't flown yet.  Say what????  There have been rocket engines on test stands like this one, but nobody has actually flown one.  The video doesn't explain why.

Yep, and the now cancelled VentureStar aerospike engines were tested on a stand, but never flew either.  Doesn't mean that they won't work, just means that for whatever reason, they never flew.