These words may sound similar, but they have very different meanings.
Conscience and conscious sound very similar and are often misused. For example, you might have heard someone say that they have something “on their conscious” when they actually mean “on their conscience.”
Conscience is a moral sense of right and wrong: My conscience is telling me that I must confess to the crime.
Conscious means aware, alert, or awake: I was conscious of a change in the weather.