I’m often asked “What’s the difference between Lingerie and Boudoir?” My retort?
“Boudoir is a fancy French way of saying I’ll shoot you in your lingerie, but not say the word lingerie”
No difference. There’s nothing major behind it, nothing to write home about. It’s a word that general portrait photographers use to try and shoot the same thing glamour photogs have been shooting for years.

Specs:

Canon EOS 5D
Natural light from the window