OceanGate Titan Submarine engineering | How it Works

Yoytube Link https://youtu.be/98uLNUCz6r0

This is not a submarine, but the Titan, is a, Cyclops-class manned submersible.

But,what's the difference between the two ?

The primary difference between a submersible, and a submarine, is that the submersible is launched from a mother vessel or home vessel.