I have seen this game described as a rogue like and a Metroidvania game so I am curious of the save system. Is it permadeath and I have to start over or is it like a Metroidvania where there are save stations ? Or is it both, that I can save but upon death my saves are erased and I have to start over ?

There is no save stations in Dead Cells, if you die you start over, no checkpoints, but if you want to quit the game you freely can and will resume where you left. (If you die you will not start over from scratch though, because you can unlock a few permanent things and bonuses for your next body).

This. The game doesn't have manual saving, but quitting the game and restarting will let you resume where you left.

The metroidvania aspect comes into play with certain upgrades you permanently unlock from various mini-bosses. These upgrades let you access different paths through the game along with "secret" areas.

The blueprints you can unlock adds to the pool of possible items/per-run abilities you can find.