The difference between regeneration and conversion is a slight difference, but it’s an important one.
Regeneration is the work of God the Holy Spirit as He supernaturally and immediately changes the disposition of the soul from spiritual death to spiritual life.
Conversion is a result of regeneration. When we are converted, we’re turned around and we move in a different direction.
Sometimes we get confused about this, because particularly when people give their testimony, they often say, “I was born again on February the 13th, 1975,” and so on. That person is testifying to a conversion experience. They may have been regenerated earlier than that but only became aware of their state of conversion at a later time.
So I think it’s important that we make sure that we distinguish between those concepts.