Confidant is someone with whom secret or confidential information may be shared: “The Prime Minister’s trusted confidant was sent to Pakistan for negotiations.”
Confidante is the female form of confidant.
Confident is being sure of oneself: “Being confident is the hallmark of a successful person.”
I am confident that a confidante is someone who never betrays aconfidence without first imposing the strictest secrecy.
Confident is the feeling some people have before they know better.