help me out here

Apparently I was cutting class the day they taught in "How TO Be a Woman 101" what exactly a "blowout" means in reference to hair. I just wonder that because I watched "Hot In Cleveland" and the Melanie character said she found a hair dresser that makes blowouts "last 14 days"...is it when they shampoo your hair and blow it dry? And then what, you don't wash your hair or anything? My mom would occasionally get her hair styled, usually an elaborate up do that she would protect by wrapping toilet paper around her head (this was the '60s & 70's) and she do that until the humidity of Baltimore would finally knock that up do flat.....if you know, help me out here. Apparently I skipped a lot of "How To Be A Woman 101" because I have no clue or skill walking in heels (to be fair, I broke my left leg at 11 and it took a long time to heal.....and when it finally healed, I got instructions to wear saddle shoes at all times).....