What is the difference between confidence and over confidence?

Answer 1:

Confidence for me means to believe in me and my hard work.

Overconfidence means believing only in me and without hard work everything is just impossible.

Answer 2:

"Only" is the one word that changes the difference between confidence and overconfidence like I can do this work is confidence and I only can do this work is overconfidence.

Answer 3:

Confidence means you can believe our ability;
I can crack the interview.

And over confidence means you can believe our ability more than our limit;
I can only crack the interview.

Answer 4:

Confidence is like an electricity which can provide proper current to light your bulb but overconfidence is like an extra electricity which can let your bulb fuse.

You can also add your answer in comment box.