whaywardj----"Everybody does it, but what IS it? What makes flirting, "flirting"?

trying to think of some examples of flirting -
1) 20th century version - The conversations in James Bond movies between Bond & women.
2) 19th century version - Jane Austen novels. Flirting of a different era.
3) 21st century - don't know. Everyone is so blatant these days.