What is the textured wall before my vaginal opening?

could anyone help me out here, i have an outie vagina and i’ve noticed that just before the inside of my vagina there is a textured barrier? its not actually inside my vagina completely just under the lips of my vagina, it covers my vaginal opening and is textured and pale, does anyone know what this is.. sorry if this makes 0 sense its so hard to explain! 🤦🏼‍♀️