It's where they separate the bag of water from the uterus by the cervix it causes a hormone to be released so the cervix can thin out more and you can dilate more as well and it also causes the uterus to contract to make labor come naturally instead of being induced
I had mine stripped at almost 39 weeks and I went into hard labor 4 hours later and birthed him that night at midnight. I hope it works for you as well!!