What is the "Unconditioned" that the Buddha is talking about? And vinjana in Buddhsm

In advaita vedanta, consciousness is the self. Consciousness has 2 modes: it can be pure consciousness, and it is described as "being aware of being aware" or the "I that I am knows that I am"; while the other mode of consciousness is consciousness entangled in objects, like feelings and thoughts. Is pure consciousness, or being aware of being aware, the same as what the Buddha called the "unconditioned"? Or is the unconditioned the cessation of consciousness, as Buddhism sees consciousness as impermanent and not self? They said if consciousness was not aware of itself, none of us would know that we are aware. I have this problem, my friend had the same, so we wanted to ask you if you could help us out.