when a domme uses the term edge play to refer to some of her interests, what does it tend to mean?

wikipedia says that it often refers to behavior more risky than the usual safe, sane and consensual.

The wiki says that it tends to mean breath play, fire play (meaning candle wax dropping or something else?), knife play, fear play, cutting and bloodplay. Apparently, for some, it also means or includes scat or barebacking in some scenes or non-condomized contact or sex.