how do penguin flippers work?

Penguins are birds that cannot fly, so how do penguin flippers work? For reference, Penguins or Sphenisciformes, are from Spheniscidae family and are mostly found in the southern hemisphere.

Penguins, unlike birds that fly, are much heavier and have have larger skeleton, more suitable for land and see, and not air. Penguins are endowed with havey bones, which actually helps them with power thrust in the water, and diving (due to increased weight).

Penguin flippers are stiff and are used like a paddle, and not like a wing. With them, penguins execute powerful thrusts. There is in fact new research in propulsion technologies that are taking advantage of the way flippers work.