Confidence is a gender-specific codeword. And there are dozens of these codewords which in cis-gender subcultures communicates far more than the members of the other gender subculture can appreciate unless they are fairly perceptive.
Confidence in the case of (traditional) women is a strange one. Women are almost universally insecure. Anyone that looks at beauty magazines can see the underlying direct psychological manipulation they represent.
Men value women more on absolutes (appearance) than women do, which is why arbitrary measures such as social graph relations like like "that guy has a lot of women that talk about him, so I find him attractive", they use dress and other indirect indicators to guess social status and wealth more than even if you outright tell them positions or wealth numbers.
What a woman means by a "confident" man is that dating the man makes THEM feel less insecure and more confident. It represents another indirect emotional measure of a man's status and wealth, likely because the group dynamics we evolved in resulted in insecure men actually not being able to provide/defend/protect mates and offspring.
Of course those indicators vary substantially by culture and individual. Of course those individuals don't understand that their personal choices aren't universal (much like men with a distinct type often are mystifying by men being attracted to appearance features they abhor).
Men are often perplexed by the confidence vs arrogance angle. I believe this is another fine-tuned evolutionary sense, where arrogance implies lack of faithfulness/devotion to offspring in the long run, and implies that, while they may be able to dominate socially, it is an unstable one. It may also be intuition that they are faking true confidence aka the ability to dominate resources.
In the land of the blind...